Hi Indu,

Yeah Sure, you can absolutely do M.A. in Sociology after the B.A. LLB course. Rather you cannot persue these two course simultaneously as attendance and regular classes is compulsory for both the courses else it's a good idea to persue M.A. after LLB as it has a very good scope for the future.
You can absolutely go for it.

Hope it helps..!!

Good Luck