Dear Khushi, I glad to guide you because as per your point of interest and your marks which you get in your curriculum is impressive. Dear, there is no need to drop one year for shake of cracking IIT, if you are that much clear about your dream that is becoming IAS then why you want to waste your one year you can do simple B.Tech side by side you just prepared for IAS or you can do graduation from Arts background if you want that will help you in your preparation.

All the best