Hey Kalyani

Yes ,Diploma students can appear for IIT admission. Diploma students who have completed their degree, or are in the final year of doing so, are eligible to apply for JEE Main 2018, but will not be given admission to NITs and CFTIs. If they qualify JEE Main, they will have to appear for JEE Advanced, and they will be given admission like class 12th pass students.

Feel free to ask if you have anymore queries. ALL The best.Hope this will help you.