my wbjee obc-a rank is 315, what college and branch can i expect ( rank in common rank list is 7983) ?

Hello Prerna,
Congratulations for your marks. Your category rank is excellent.
As per your general rank, it's little difficult for you to get a seat in top colleges but with your OBC rank, there are many chances that you will get one. I have searched for you some colleges where you can apply for admission.
1) Jadavpur University (IT, Mechanical, Electrical)
2) Calcutta University (CSE)
3) MAKAUT - Maulana Abul Kalam Azad University of Technology (CSE)
4) KGEC - Kalyani Government Engineering College (CSE)
5) A.K. Choudhury School of Information Technology, University of Calcutta (IT)
6) Heritage Institute of Technology (CSE)
7) IEM - Institute of Engineering & Management (IT)
Hope this helps you.
ALL THE BEST.