What is band 7B in IBM India?

It is a managerial position (similar to a Project Manager in the market) in IBM. When offered, you are expected to lead a team and would be responsible for it's growth. 7A is offered to candidates with 8+ years of experience when the same experience includes a Project Lead/Manager role as well.

7B is a senior project manager cadre and the same requires very good experience in the project management track. Generally I think, IBM offers 7B for candidates with 10+years of experience.