Hi

For clearing and getting a rank one needs to clear all the sectional cut off and of that particular category. If one fails to pass any sections even by one number he/she is termed as non-egligble. But you have the same scores as that of physics in the other two then it's possible that you'll get a decent rank.

But can't ensure you about the IIT as the rank VS marks varies every year and it's differernt for every category.

all the best

cheers!