NIT

100+ score is enough to get into NITs

You need to cleat IIT-JEE Mains to get into NITs. A score around 220-250 is a good scored to get into NITs. At this score, you have high chances to get computer science branch in top NITs.
Good Luck.

NITs do not offer full-time e-commerce degree courses. Is your question on NIT or NIIT?

Hi,
All information you need can be accessed from here:
http://www.criteria.in/nimcet-exam-2017-online-apply-eligibility-exam-dates/
For preparation, you can first attempt last few years' papers and see how much you know and what all needs to be practised and then decide the time or coaching you need to crack it. There could be specific sections or over all preparation.

Hi,
You can check the below mentioned link:
https://www.shiksha.com/news/jee-main-2016-expected-cutoff-article-12329-1

The JEE Mains cut off for general category is 100. But, to get a seat in NITs, you need to get score above 220 marks. You also need to score 75% in your class 12th.

You can consider:
1. BITSAT.
2. SRM.
3. COEP.
4. VIT.
5. AMRITA.
All the best.

The required cutoff is 48 marks, but if you want to get admission in your preferred branch then you need to have a score around 100 marks.

Yes, you can get admission. If you are from a reserved category, then you can get top NITs.
All the best.

With 30, 000 rank, you won't be able to get a seat in NIT. You can try in some other government college.