Hello shivam,

It depends on which is your preferred branch and which particular nit you are aiming for.If you will go for top Nits like warangal,Surathkal,Rourkela,nagpur and want top branches like CSE,ECE,EEE,IT than you have to get a rank of below 8k to 7k.

For further NiTs you can  get those branches by securing a rank of less than 10k.

Now speaking about percentile keep an aim of getting more that 96-97 percentile.

Hope it will help 

Thankyou