the chances of getting a college in a particular course depends upon the ranks scored in JEE mains exam . it is very hard to predict the rank from the percentile as jee mains exams was held at different sessions and the rank may vary a lot from the predicted rank so the best way is to check out the previous year NIT cutoffs .here is the first round cutoffs of 2018

https://d2cyt36b7wnvt9.cloudfront.net/exams/wp-content/uploads/2018/04/02163624/nit-cutoff-2018-r1.pdf

but i will advice you to wait for the josaa counselling for NIITs 2019

best of luck