Exam

You need above 180 for an outsider SC student and 130+ for a Delhi SC student.

JEE Mains result have already been declared and CBSE provide two chances to make any correction in the application form, so any sort of change at this moment will not be entertained by CBSE , you can still write to CBSE and discuss your case (contact - http://jeemain.nic.in/WebInfo/Public/View.aspx?

https://www.shiksha.com/top-mba-colleges-accepting-mat-score-article-6056-1
Complete list of top tier MBA coll with MAT acceptance has been given above along with paper pattern for MAT.

for st category 130+ in mains and 80%+ in board are safe
pls upvote

Sorry to say but it is quite difficult to get NITs. However, if you prefer IIIT and GFTI in Josaa counselling you may get CSE branch.
Kindly, upvote.

Thapar University, all private IIITs like IIIT Hyderabad, IIIT Bhubaneswar and many other good engineering colleges offer admission on basis of JEE Mains marks only.

It depends on what package you take as its Your ability to cope up with the syllabus. Generally it can be 3 months to 15 months.

hello
IIT had introduced there preparatory course 3-4 years ago for sc/st and pd candidates
under this those candidates r selected who just missed to get least marks under there category qualification.
this is a one year course,will be commence by IIT itself
after one year completion u will b tagged eit

It is easy, you have to fill the form that is available on the website of UPSC.