Hi Shubham, in my opinion, ) University of Calcutta is a good option. The faculty there is very good with utmost experience. The alumni network is tremendous which really helps freshers. 

But the placement scenario is not that good. And also the grading system there is pretty tough and rigid.

I suggest you to research more about it and then decide if it suits you best 

Hope this helps. Regards

Hello Aspirant, Calcutta University has extremely good Natural Science Department,  this is the best in India. It's Undergraduate (BA/B.Sc) are taught in several colleges under Calcutta University. While M.Sc is taught in Calcutta university only. This is one of the best university. 

I hope this will help you.