With 90 percentile, I assume your rank is around 1 lakh to 1.5 lakh. But the cut off rank for all IIIts for addmission is around 32000-35000 fir general category. The cut off rank is different  SC/ST/OBC category.

So with 90 percentile,  you have negligible chances of getting admission in IIITs.

With 90 percentile, I assume your rank is around 1 lakh. The cut-offs for all IIITs for admission in any course is around 32,000 for general category. So given your percentile, you have negligible chances of getting admission in CSE or any other stream in any IIIT.