Hi Anubhab,
3926 is an amazing rank in SRMJEE and with such a good rank you can pursue any of the branches in any of the campuses( including CSE, IT)
but as per your convenience, the main options that are available to you are:-
1) Biomedical engineering at Chennai campus
2) Biotechnology engineering at Chennai campus
3) Genetics engineering at Chennai campus
4) Biomedical and Biotechnology engineering at Sonipat campus.

Of these, I would suggest you go for the Chennai campus as it is better established and have better faculties then Sonipat campus.
Hope it would help.
Thank you.