hello,

No you can't get an admission in NIT like that. It is okay if you scored 90 in your school or intermediate. You have to appear jee main and have to secure a rank that will make you eligible to get an admission at any NIT campus across India.

To appear jee main you have to prepare yourself for the exam by practicing the numericals and solving the question from the syllabus mentioned chapters.

If you are good at PCM, and you did your best in it your intermediate then you have remembered most of the concepts and it will be easy for you to solve them fast.

Practice more and also previous year papers to know how questions are asked in the entrance.

Hope it helps!