Hey Shubam.
You will have to take the JEE Mains exams in order to take admission in IIITs. Your chances for admission will depend on your score and rank in the JEE mains exam. You can use the link below to find out previous year cut offs for IIITs.
https://www.google.co.in/amp/s/engineering.careers360.com/articles/jee-main-cutoff-for-top-iiits%3famp
Best of luck!
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile