It is normal to desire for IIT and top class institutes. There are many institutes which conduct tests when they take in students for coaching. I suggest that you write that test. Then you the expectations of the coaching centers.
Try looking at the lessons of the persons who are in the coaching for IIT. If you think you can do it, if you think you have liking in the subjects and have determination to continue in spite of difficulties, continue with it.
If you want to play safe and be happy with regular syllabus and are able to do well with that, that option is also not a bad idea. What is important is to feel interested in what you are doing and be successful in that. It is better than going for IIT and then not being able to do well in that. Talk to one or two students one year senior to you. It will give you an idea. You don't have to take their decision. You take your decision.