What is the fee for SC/ST students in IIM A, B, and C?

There is no concession for SC/ST students in IIM A, B and C. But this is not a major issue.

IIMs offer a lot of financial aid services to financially weak people. In some cases, the entire fee is paid by the college or some part. It depends on the judgment of the panel on the basis of your situation.

All IIMs offer educational loans at a relatively low interest rate. Banks usually consider IIM students as a profitable investment. So rather than worrying about the money, focus more on your goals.