If we have a look at the cut-offs for the Scheduled Tribe population at Indian Institute of Technology, Bombay, then the cut-offs for the session 2021 were as follows:

Aerospace Engineering: 504
Chemical Engineering: 431
Civil Engineering: 149
Computer Science and Engineering: 11

So, in general these are the ranks you'll require to secure a seat at IIT Bombay. Hope I have answered your question. All the best!