Hey, With this percentile it will be difficult for you to get into Top 15 NIT but you also belong to SC Category then you can try to other branches too.

But You can apply for CS in other good colleges too.

I will recommend you to check All The Colleges, That is available for You on basis of your rankings and Reservation, Then You can also check that at Our JEE MAINS COLLEGE Predictor. That will be very helpful for You.