Well preparatory courses are being given to those SC St or pwd candidates who are not able to clear the cutoff and their are still seats vacant for these reserved categories. So these seats need to be filled. 

So all these seats will be declared once the complete admission procedure has taken place and in the last if still some seats remains vacant of the reserved categories then they will be given in form of preparatory courses

Hi kamlesh,

most of IITs offer preparatory courses for candidates from SC/ST/PwD Candidates. These preparatory courses are basically bridge courses which are meant to prepare underprivileged candidates to perform better in the UG programs. 

List of candidates selected for admission to preparatory courses would be released soon after the declaration of jee Advanced results. All the conditions and rules for admission to preparatory courses is explained below for the reference of the candidates.