NIT

Getting a seat by donation is ruled out.You get a seat only with a good rank.

Hello Naveen,
Yes, you need to give JEE Mains and secure a good rank like 20000 and below to get good NITs. You need to prepare separately as the questions are from PCM based on class 11&12 syllabus (NCERT).

NIT is a better option for pursuing M.Sc in maths.

Hello Gourav,
Yes, it is so. For general category, it is compulsory to have at least 75% and for SC, ST and PWD candidates it is necessary to have at least 65%.
Even if you don't have 75%, it is mandatory to be in the top 20 percentile that is the top 20% of students on your board. if you don't satisfy these conditions then you cannot get any colleges under JEE counselling.

Sir, if you are talking about JEE rank then sorry you can get admission only in B.Tech course through this rank but unfortunately, this rank is not too good to get NITs or IITs. So if you are thinking for B.Sc, then go in any other college.

You won't get NIT with this rank. Try for government colleges.

Hello Manish,
As per your rank, you will surely get lower NITs but wait till the last phase of counseling, however, check here to know more:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor

Hi JY,
You can check this college comparison tool provided by Shiksha:
https://www.shiksha.com/resources/college-comparison

Hello Shashikant,
You have very low or no chances to get a NIT or IIIT as your rank under SC category is 15000. You may get a college by your home state rank (if any colleges are in your state).
You may refer below link:
http://josaa.nic.in/Result/result/OpeningClosingRank.aspx