Dear Abhishek, your Category has got nothing to do with preparation for an exam. It depends on the hard work you put in and how determined you are. This prrparatory course is specifically for SC/ST/PWD students. The IIT Preparatory Course comprises of courses in Mathematics, Physics, Chemistry and English for two semesters after which the candidates are evaluated. The preparatory candidates are first given grounding in acquiring conceptual understanding for a year and only after they pass an exam towards the end of the year are they allowed to pursue a degree from the institute. So this is one chance for you to get into an IIT if you have been dreaming for one.