Hello Ananya,

The eligibility criteria for IIITs/NITS/GFTI's for SC category students is 65% for Class 12 or equivalent exam. This criteria is after writing the exams. You have the criteria and you can easily get into IIITs. To know more about which IIITs you will get at your rank you can use our college predictor link :- https://engineering.careers360.com/jee-main-college-predictor

Regarding the Gap year, if you have taken the JEE MAIN exams this year i.e. in 2019 then you will have no issues because the eligibility criteria says Students must have passed Class 12 or equivalent in 2017 or 2018 and also students who are appearing in 2019 are also eligible. Please read on our link for better clearity :- https://www.google.com/amp/s/engineering.careers360.com/articles/jee-main-eligibility-criteria/amp

If you are still facing any issues,do let me know. All the best for future!!