HI,
It is good that you are clear about your aim.
First of all, in this upcoming two year journey, most important is that you have to be sincere, and honest to Yourself. You have to be ready to work hard in proper direction. Seek right guidance., join a coaching institute for good exposure. Dont waste time.
Start from day1. IIT is not easy.. you need to work for it.
This does not mean that you should always study. take a break. Dont be stressed . Enjoy what you study.
Have a good hold on concepts. Clear your doubts, learn from mistakes. solve papers..
So , first plan everything up, make a time table, and follow it up sincerely. Dont make excuces..
ALL THE BEST !!