NIT

To get admission in NITs and IITs, you need a strategy. You need to make your basics clear and rigid so that you can move forward. You can read NCERT books. You should practice as it will help you to understand the theories in a better way and also you will come across some unknown methods to solve a particular problem.
You can collect the previous year question papers with their solutions as it will help you to analyse the pattern. You should revise the areas in which you are strong, but work on the areas in which you are weak.
Best of luck.

BITS-Pilani, VIT University, Manipal University, Thapar University, SRM, BIT are recommended options. You may refer to following link for ranking of top engineering colleges in India: https://www.shiksha.com/top-engineering-colleges-in-india-rankingpage-44-2-0-0-0

You need to score around 150 marks to get admission in NITs.

If you belong to general category then you need to score more than 150 marks.

You need to qualify JEE Mains exam to get admission in NITs.

You need to qualify JEE Mains exam to get admission in NITs and JEE Advanced exam to get admission in IITs.
Kindly visit the link mentioned below to know about the colleges offering B.Tech in biotechnology:
https://www.shiksha.com/top-bio-technology-colleges-in-india-rankingpage-54-2-0-0-0

My recommendation on your choices is as follows in order of precedence: IIT, NIT, VIT. These are based on brand image, career opportunities, growth and other factors.

Hi,
It entirely depends on the cut off of that particular year. But getting 230+ would ensure your admission in CS in good NITs. In case of IITs you need to just qualify JEE Mains but have to do well in JEE Advanced.

Hi,
There is a list released by the JEE Mains counseling department every year regarding all the opening and closing rank of different colleges (both other state and own state category wise). You can check that or you can check the website of NIT, Jalandhar.

There is no difference for student studying in NIT and other studying in IIT.There is only thinking that go for IIT only.There are NIT'S which are far better than some IIT like NIT Allahabad it ranks above some reputed IITs.So don't let your career fix to IIT only if you are getting a good NIT go for it.