Hi ranga
Thanks for asking your query, congratulations on securing such a good percentage in 12th but to get NIT or govt college you have to give entrance exam that is Jee mains according to your rank and percentile you will be allotted college with your desired branch.
Hope this will help you

Hello Swaroop
Actually to get into the NIT not only 12th marks are considered meanwhile you should have a required cutoff percentile in the Class 12th
So that you Can get into it by the above mentioned way with reaching there essential requirements
Best of luck