Hey Biswaprakash

Besides the societal advantage and the fact that it will make your parents proud the factual benefits you will get from IIT are a great faculty who will lead to better understanding of the subject with clarity in the topics (which honestly you wont get in most colleges in India), You will be preferred for a job in many MNC companies or even in schools if you want to get appointed as a teacher and besides just forcing you to focus on your grades you will get great opportunities to do extra  curriculum activities   like music, event management, sports, attending various seminars, participating in drama, creative writing, etc.