Hi Jay,

Preparatory courses are some sort of special courses that I checked are given to SC/ST students. Once you get into these courses, you will be given one year training about the 11th and 12th topics in physics,chemistry and maths I believe by the various IITs. Only if you successfully complete this course,you will be declared as 'pass' or 'fail' ,if pass, you will be eligible to apply for the normal 4/5 year programmes at various IITs.

Best wishes!