National Law School of India University (NLSIU),Bangaloreis often considered the best law college in this country. It would be advised to you that even if you get this college at the age of 20 you should just go for it. There should not be any age bar for learning and achieving anything.
Bachelors of Arts + Bachelor of Law (BALLB) is a five-year program and the students are admitted on the basis of score in CLAT.
It is highly advised that if you have not got into any college yet and is having second thoughts about taking a second-year drop, you should avoid doing that if you have a decent alternative law school.