Hii Viswa..For the same branch, a four year course is always better than a five year one because of -

1. If you want to do Masters - If you are such a good student that you are doing Bachelors from IIT, then you can do Masters some of the best colleges of the world, abroad. They are certainly a better option than Masters in IIT.
2. If you want a job - If you take a 5 year course, then after 4 years, your counterparts will already be placed and have a working experience in industry of 1 year, and will be much ahead of you as you will just be starting your job as a freshman pass-out.
3. If you are not sure whether you want to live with the branch for your life, changing your work domain after Bachelors is much easier than after Masters.

Hope this helps you. All the best.