The eligibility criteria for admission to various NITs/ IIITs says that a student has to score at least 75% in his 12th board or has to be in top 20% percentile of his/ her respective board.

So, as the information shared by you, you satisfy this criteria but the main thing is to clear the cutoff for the particular institute.

For ex. If you want to take admission in CS at NIT "XYZ" then you must have to clear the cutoff (JEE Main Rank) for this NIT along with the minimum marks to be scored in 12th Board exams.

So, please check the cutoff ranks for the institute you want to take admission in.

You can check the last year cutoff ranks using the link provided below:

https://josaa.nic.in/webinfocms/Public/View.aspx?page=71

For any other information regarding counselling, cutoffs, etc. use the B.Tech companion from the link provided below:

https://www.careers360.com/btech-companion