Brahmins Generation and their Gotra system.

Brahmin gotra system
The word "gotra" means "lineage" in the Sanskrit language. Among those of the Brahmin caste, gotras are reckoned patrilineally. Each gotra takes the name of a famous Rishi or sage who was the patrilineal forebearer of that clan. And each Gotra is addressed by the suffix 'sa' or 'asa' as relevant.
The concept of Gotra was the first attempt among Brahmins to classify themselves among different groups. At the beginning, these gents identified themselves by the names of various rishis (Angirasa, Atri, Gautam, Kashyapa, Bhrigu, Vasistha, Kutsa,and Bharadwaja; the first seven of these are often enumerated as Saptarishis). It is to be noted that Vishwamitra was initially a Kshatriya king, who later chose and rose to become an ascetic rishi. Hence the gotra was applied to the grouping stemming from one of these rishis as his descendants.
List of Brahmin Gotras
The following is a partial list of gotras found in the Brahmin community of Hindus:
 Agastya, Atreyasa / Atri, Alambani, Angad, Angirasa, Ahabhunasa, Aupamanyava,
 Babhravya, Bharadwaja, Bhargava, Bhakdi, Bhaskara,
 Chandilya, Charora, Chikitasa, Chyavana,
 Dalabhya, Darbhas, Dhananjaya, Dhanvantari,
 Galvasaya, Garga, Gautamasa, Gaubhilya,
 Harita/ Haritasa, Hukman Bhal,
 Jamadagni, Jatukarna,
 Kalabodhana/ Kalaboudha /Kalabhavasa, Kamakayana Vishwamitra, Kanva, Kaushikasa, Kapi, Kapil, Karmani, Kashyapasa, Kaundinyasa, Kaunsh, Kaushal/ Kaushalas / Kushal, Kaushik/Koshik/Koushik, Kushika, Kaustubha, Kausyagasa, Kavist, Katyayana, Krishnatriya or Krishnatreeya,
 Kundina Gowtama,Kutsa, Kutsasa
 Lakhi, Lohit, Lohita-Kowsika, Lomasha,
 Mandavya, Marichi, Markandeya, Mauna Bhargava, Matanga, Maudgalya Moudgalya,
 Mudgala (Maudgalya, Moudgil, Modgil, Mudgal), Mudgal
 Naidhruva, Nithunthana/Naithunthasa, Nydravakashyapa, Nrisimhadevara,
 Parashara, Parthivasa, Pouragutsya, Ratheetarasa, Purang, Pradnya, Pratanansya
 Rathitara, Rohinya, Rauksaayana, Roushayadana,
 Saminathen, Sanatana, Salankayana, Sangar, Sanaka, Sanaga, Sanjaya, Sankhyayana
 Sankrithi(Sankrityayan), Sankyanasa, Sathamarshana, Shandilya , sanas, Sandilyasa, Shandelosya,
 Saawarna, Saharia Joshi, Sauparna, Savaran, Savita. Somnasser, Saankritya(Sakarawar),
 Soral, Srivatsa, Sumarkanth, Suryadhwaja, Shaktri, Shaunaka, Surya, Swatantra Kabisa, Suparna,
 Tugnait * Upamanyu, * Upadhyay, Utsasya,
 Vadula, Valmiki, Vardhviyasa, Vardhulasa, Vardhyswasa, Vashishta, Vatsa, Vatsyayan, Veetahavya, Vishnu, Vishnuvardhana, Vishnuvruddha, Viswamitra, Vishvagni, Vartantu, Vishwagni, Vaidya/Baidya,
 Yaska

Brahmin communities
Brahmin communities in India are traditionally divided into two regional groups: Pancha-Gauda Brahmins and Pancha-Dravida Brahmins according to the following shloka found in the Rajatarangini of Kalhana (12th century):

कर्णाटकाश्च तैलंगा द्राविडा महाराष्ट्रकाः ।
गुर्जराश्चेति पञ्चैव द्राविडा विन्ध्यदक्षिणे ॥
सारस्वताः कान्यकुब्जा गौडा उत्कलमैथिलाः ।
पन्चगौडा इति ख्याता विन्ध्स्योत्तरवासिनः ॥
कर्णाटकाश्च तैलंगा द्राविडा महाराष्ट्रकाः ।
गुर्जराश्चेति पञ्चैव द्राविडा विन्ध्यदक्षिणे ॥
सारस्वताः कान्यकुब्जा गौडा उत्कलमैथिलाः ।
पन्चगौडा इति ख्याता विन्ध्स्योत्तरवासिनः ॥

"The Karnatakas, Tailangas, Dravidas, Maharashtrakas and Gurjaras; these five (-types who- ) live south of Vindhya (- mountains) are (called-) "Dravida" (- brahmins); (whereas-) Saraswatas, Kanyakubjas, Gaudas, Utkalas, and Maithilas, who live north of Vindhya (- mountains) are known as "five Gauda" (- brahmins)."
The shloka only identifies the caste-system present on the basis of their regional presence. The classification of Brahmins, the highest varna, on the basis of Region is debatable (compare the Brahmin gotra system).
Pancha-Gauda
Main article: Pancha-Gauda
Those from Uttarapatha (Aryavarta) (northern and eastern India.)
Approximately ordered according to geographical regions, from West to East
Saraswat
 Kashmiri Pandits
 Mohyal Brahmins
 Rajapur Saraswat Brahmins
 Gouda Saraswat Brahmins
 Punjabi Saraswat Brahmins
 Rajasthan Saraswat Brahmins
 Chitrapur Saraswat Brahmin
 Nasarpuri Sindh Saraswat Brahmin
 Brahmbhatt Brahmin
Kanyakubja
 Kanyakubja Brahmins
 Saryupareen Brahmins
Gauda
 Khandelwal Brahmin
 Kota Brahmin
 Dadhich Brahmin
 Gaur Brahmin
 Sanadhya Brahmin
 Shri Gaur Malviya Brahmin
Sanskrit gauḍa is a vrddhi derivation of guḍa, literally "sugar molass", but also the name of a tribe of the Madhyadesha. A school of thought believes that Gauda is sometimes taken to mean the Gaur region of Bengal. However the original meaning of the term coincides with region termed as Brahmakshetra:
ब्रह्मक्षेत्रं गुडारण्यं मत्स्यपाञ्चालमाथुराः
एष ब्रह्मर्षि देशो वै ब्रह्मावर्त समम्बरम् ॥
ब्रह्मक्षेत्रं कुरुक्षेत्रं ब्रह्मदेशः प्रकथ्यते
आदिगौदर्षिदेशान्तं हर्यारण्यमिहोच्यते ॥
Bengali Brahmins
Utkal(Orissa) Utkala Brahmins
Maithil Brahmin (Mithila) Maithil Brahmins

Pancha-Dravida (Five Southern)
Those from Dakshinapatha (South India, including Gujarat and Maharashtra).
Gujarat
Trivedi Mewada Brahmin ,Migrated from Mewad, Rajasthan during time of Great King Rana pratap to Gujarat some 434 years ago. i.e 1576 to 1590 (Since battle of Haldighati was happened during June, 1576). But prior to that only as a precautionary steps King Ranasinh Pratap has requested Brahmin Community to migrate to safe place (being Akbar was Muslim emperor and may take wrong steps on Brahmin Community, since Brahmin were doing all Prayers for GOD in those days). But King Ranasinh Pratap requested that you should be continue worshiping Eklanji Mahadev only. Which is still continued by all Mewada Brahaman Community.
As per some articles (source: Book in Gujarati -"Dabo Melyo Mewad") it is understood that during 1280 under the leadership of Mr. Mahanand Trivedi 999 Brahmin shifted from Mewad towards Gujarat and near Tahsil: Bhiloda there is a Village called "Narsoli" they established Eklingji Shivalay. This migration is due to contineous Muslim attacks on Mewad and harassing Brahmin community specifically. In the same book it is referred that during 1303 Allhuddin Khilji has killed 640,000 brahim male members and thrown their scared thread (Janoi / Ugnopavit / Upnayan / Janva) in 1600 litters of blood. As per some views there were 10,000 brahmins and blood sheds were abouts 30 litters. To avoid these mass killings Brahmin community migrated towards Gujarat.
Also you get website like http://www.brahmsamaj.org
Rajgor Brahmin
 Bhatt Mewada Brahmin ,Migrated from Mewad, Rajasthan during time of Great King Rana pratap to Gujarat some 250 years ago. i.e 1750 to 1760
 Chauriyasi Mewada Brahmin from south Gujarat, Migrated from Chittod, Rajasthan some 800 years ago to Dharampur near Valsad. i.e. 1158 AD to 1168 AD
 Saurashtra Trivedi Mewad Brahmin
 Saurashtra Bhatt Mewada Brahmin
 Pushkarna Brahmin
 Nagar Brahmin
 Khedaval Brahmin
 Audich Brahmin
 Modh Brahmin
 Bardai Brahmin
 Girinarayan Brahmin
 Shrimali Brahman
 Anavil Brahmin
 Sidhra-Rudhra Brahmin
 Sree gauda Brahmin
 Rajgor Brahmin Basically comes from Rajeshtan
 Prashnora Brahmin
 Kanaujiya or Kanyakumbj Brahmin migrated from kanoj,entered in kutch via sindh along with lohanas have surname Bhatt in kutch,divided as bhuvdiyas,vondhiyas,sandhliyas according to their village temple.others in Gujarat mainly found in jamnagar,morbi,junaghath and rajkot.surnames like Bhatt,Kaileyas,bhaglani,pingal,lakhlani,ghediya etc are common.
Maharashtra
 Deshastha Brahmin
 Chitpavan Brahmin (Konkanastha)
 Karhade Brahmin
 Devrukhe Brahmin
Karnataka
 Kannada Brahmins
 Babbur Kamme Brahmins
 Badaganadu Brahmins
 Deshastha Brahmin
 Havyaka Brahmin
 Hasan Iyengars
 Hebbar Iyengars
 Hoysala Karnataka Brahmins
 Karhade Brahmin
 Koota Brahmins
 Madhva Brahmins
 Mandyam Iyengars
 Mysore Iyengars
 Niyogi Brahmins
 Panchagrama Brahmin
 Sankethi Brahmins
 Shukla Yajurveda Brahmins
 Smartha Brahmins
 Srivaishnava Brahmins
 Sthanika Brahmins
 Ulucha Kamme Brahmins
 Mysore Iyers
 Ashtagrama iyers
 Mulukanadu Brahmins
 Tuluva Brahmins
 Kandavara Brahmins
 Karhade Brahmins
 Maratha Brahmins
 Padia Brahmins
 Saklapuri Brahmins
 Shivalli Brahmins
 Smartha Shivalli Brahmins
 Sthanika Brahmins
Andhra Pradesh
 Telugu Brahmins
 Niyogi Brahmins
 Vaidiki Brahmins
Tamil Nadu
 Iyengars (sub-divided into Vadakalai and Thenkalai)
 Iyers (sub-divided further into Vadama, Vathima, Brahacharanam, Ashtasahasram, Gurukkal, Dikshitar, Kaniyalar, Prathamasaki, dravida brahmins)
 Kerala
 Namboothiri Brahmins
 Kerala Iyers
 Embranthiris
 Pushpaka Brahmins (Ambalavasis}
 Sharada Brahmins
 Nagariks or the Brahmin migrants from north India
List of sub-castes
Some of the existing sub-castes from Panch-Gaur group of Brahmins are:
 Assamese Brahmins
 Brahmbhatt Brahmin
 Bengali Brahmins
 Bhargav Brahmins
 Dadhich Brahmins
 Dube Brahmins
 Gaur BrahminsMainly Adi Gaur brahman which includes Gaur,Tyagi,Pachauri,Gautam etc mainly residing in Haryana,West Uttar Pradesh and Rajasthan.
 Gautam Brahmins
 Jangid Brahmins
 Kashmiri Pandits
 Khandelwal Brahmins
 Khedaval Brahmins
 Mohyal Brahmins
 Kanyakubja Brahmins
 Kota Brahmins
 Kulin Brahmins
 Maithili Brahmins
 Rajapur Saraswat Brahmins
 Sanadhya Brahmins
 Saraswat Brahmins
 Saryupareen Brahmins
 Shakdwipi Brahmins
 Shrimali Brahmins
 Suryadhwaja Brahmins
 Tyagi Brahmins
Some of the existing sub-castes from Panch-Dravida group of Brahmins are:
 Bardai Brahmins
 Chitpavan Brahmins (Konkanasth)
 Daivajna Brahmin
 Dhima Brahmins
 Deshastha Brahmin
 Gouda Saraswat Brahmins
 Havyaka Brahmin
 Hoysala Karnataka Brahmins
 Iyers, Iyengar (Vadakalai Thenkalai )
 Kandavara Brahmins
 Kannada Brahmins
 Karhade Brahmins
 Koota Brahmins
 Koteshwara Brahmins
 Nagar Brahmins
 Padia Brahmins
 Pushpaka Brahmins (Ambalavasi Brahmins)
 Saklapuri Brahmins
 Sankethi Brahmins
 Shivalli Brahmins
 Sthanika Brahmins
 Telugu Brahmins (Vaidiki, Niyogi)
 Tuluva Brahmins