To become a corporate lawyer you need to complete your law degree.

Now,you have two options.

1. Choose any undergraduation program like BA,Bcom,BSc etc. and complete it.After doing that apply for a LLB in any university.
Eg.
1.Delhi University
2.Banaras Hindu University etc.

2.Appear for Common Law Entrance Test (CLAT) and do an integrated BA LLB course from a recognised university.
Eg.
1.NLSIU, Bangalore
2.NLU ,Delhi
3.NLU , Hyderabad

3.After completing your degree you need continuous education and research.

Tips-
Nowadays students are preferring doing integrated course because it can save their one year.