Hello dear, firstly congrats you have scored really well,

Coming back to your question in AIR 875, considering you a general category student these are the IIT’s you’ll likely to get.

Core branches like Mech, civil, Ece in the below listed iit’s

IIT KANPUR , IIT KHARAGPUR, IIT MADRAS, IIT GUWAHATI, IIT ROORKEE, IIT VARANASI

And CSE in new iit’s.

IIT DELHI , IIT BOMBAY very little chance of getting even mathematics and scientific computing.

And one thing I would like to add if you are getting non CS branch like EEE or ECE and Mec in old IITs  go for it, as there you will find lots and lots of exposure in every filed from tech to non-tech, a really awesome crowd, lots of opportunities, freedom whereas new IITs lags in all these things. Additionally, branch change is also possible there if you perform really well in your 1st year.  And are several information regarding this branch change, so if you are interested in knowing them, do comment I will get back to you.