Why not you can get NIT Because you cleared all eligibility criteria 

You cleared jee mains 2019 general cut off

You cleared 75percent board criteria so you can get nit if you are not from general category because at general Category you have less chance to get any nit because according to you percentile I can imagine your rank will be above 1lakh. So it is difficult if you are from general category but never loose hope you can get seat in you home state .And give exam of jee advance and do your best!