If your ultimate aim is IIT, forget SRM, take a year drop, join a coaching institute and work your pants off. By joining an college, you would be reducing your JEE preparation time as well as hampering the study time required for that college. I am not saying it can't be done. Loads of people have done it. But remember its difficult as hell. So, you can join a college ... but make sure you can work relentlessly the whole of this year.