Requirements to get into GLC or for that matter any college in Maharashtra for a 3yr LLB course :

Graduation

CET appeared

Domicile certificate if not then you're treated as OMS candidate

So, inorder to get into a 3yr course you've to be a graduate first. Here SSC or HSC marks do not matter. Also you've to be in rankings to be able to secure a seat.

Caste system does not apply for OMS candidates. It's only for a Maharashtra State candidate but during getting admission to hostels OMS candidates have a special quota.