Hey.

If you are already a btech graduate then you do not need to do the 5 year Integrated  BA LLB in order to pursue law. You can just pursue a 3 year law degree.

There are two types of law degrees in India. 5 year Integrated courses that combine an undergraduate degree and law which is suitable for 12th passout more. If you've done an undergrad in any field even btech you can straightaway pursue a 3 year law course. According to most colleges for 3 year law you'd require a minimum aggregate of 40-50% marks in UG degree to be eligible. Chances of admission depend on the various entrance tests.

Best of luck