Hii Swapnodeep..

The ranks in the ju webpage for SC closing rank is GMR that is General merit rank not SC category rank.

For example if round 1 of Jadavpur University CSE has 826 as the closing rank of CSE then year 826 is General merit rank not SC category rank.

It is applicable for all the categories not only for SC category as all the ranks provided are general merit rank not any category rank.

Hope it helps. 

Best of luck for your future.