First of all I can say that if u want to get in to IIT u want to get through JEE.For that u must be strong in maths bcz there is a minimum cut off for each subject and it requires a strong conceptual n problamatic skills in P.C.M .
Comming to the infrastructure n Faculty that is IIT my dear n there is no nead to worry abt them .
as far as my knowledge IIT-K is good for research