International Work Passport
A degree of law from an UK college will not only allow you to practice in India but you can also practice law in the UK itself.  However, just a three year course leading to LLB, does not allow you to practice, it is just an academic degree. You need to be a solicitor or barrister before you can actually start practicing. A degree from the UK will allow you to practice on behalf of clients irrespective of their location.

Employment advantage
After becoming a barrister and returning to India to practice law, your international exposure will help you get an advantage over others. Even companies dealing with international clients would be willing to accept you because of your international exposure.

Pedagogy
Though law schools in India more or less meet international standards, they are however, mostly theoretical. On the other hand, practical skill-based approach is followed in UK colleges.

Duration / Course Options
You will complete your law in 4 years in the UK (LLB 3 years + LLM 1 year) while in India the duration is longer. In India, the choice of courses is very limited while you have unlimited choice in UK colleges.