Hello student,

You have scored a decent percentile. Your JEE Main All India rank will be approx 20k - 21k.

According to  previous year cutoffs for core branch like computer science and information technology in top 10 NITs as a general category  candidate you need a percentile above 98 percentile. 

But don't lose hope as percentile vs rank ratio varies year to year. 

Hope it helps. 

Thank you :)