You know the cutoffs change every year so it is quite unpredictable. Now going by last year's cutoffs, you have fair chances of getting a seat in any of the NITs as NITs seats almost get filled within 30000 to 40000 rank. Getting computer science in top NITs such as NIT Trichy, Rourkela, Warangal, Surathkal, Nagpur may be difficult as these seats get filled within 8000 to 10000 rank. But you can expect Computer Science in NIT Patna, Raipur, Jalandhar, Pondicherry, North East NITs, NIT Sikkin, Srinagar etc. But if you look for Top NITs, you can expect other branches such as Civil, Electrical, Electronic ans Communications etc. However you haven't mentioned your home state quota, as the cutoffs are less in respective home states so you can apply for that. You can check the cutoffs here
http://engineering.careers360.com/articles/nits-cutoff-for-top-btech-branches
But keep in mind these are based on previous year data and this year cutoffs may change. So I would suggest you to use Jee Main College Predictor tool to know where you have good chances
http://engineering.careers360.com/jee-main-college-predictor?icn=QnA&ici=qna_answer