Hello, 

I would suggest you check out last year cut off for the college you want,  it will help anticipate this year cut off as well

Also Your admission through NATA is based on your merit system. Divide the NATA score by 4, and your CBSE result by 2, and add them to find your merit out of 100. Normally colleges accept a student who has 60+ merit overall, and sometimes colleges even go for lower merit. You can check out 

Https://engineering.careers360.com/colleges/ranking/2018/top-engineering-colleges-in-India-accepting-nata-score?page=1

you decide the correct colleges according to your rank and your score

All the best 

I hope this helps