Dear Marshan,
Application and admission policy of one institute may differ from any other. So, you have to follow the process according to the stipulated policy of that particular institute. For example application process for Calcutta University BA LLB 2018 (Total seats 1500) is going on and June 26 is last date for applying. One can apply Online for taking part in the entrance exam.

One can do BALLB from The Tamil Nadu Dr. Ambedkar Law University, For prospectus follow the given link Last date for form Submission @ TNDALU is June 29 .

You can also do Five year LLB programme from SGGSWU Fatehgarh Sahib (Last date Aug. 14). Both Universities give admission on the basis of marks obtained in Class 12. I hope it helps.