JEE Main

If you are a student from general category, you can't expect mechanical branch in any of the IITs/NITs.

Absolutely not required. Just 3 previous years are enough.

It is next to impossible. I would suggest you to join a coaching institute.

If you mark a question in OMR online, you cannot correct it.

DU doesn't have B.Tech course. You have to either sit for JEE Mains or go to deemed universities.

NCERT, Arihant objective chemistry and a magazine which has JEE Mains question papers. You can solve previous years question papers and take online mock tests.

The JEE Mains exam syllabus consists of the topics from class 11th and 12th. Although, class 12th has more weightage in JEE Mains exam. Generally, it has 40:60 ratio. 40% for class 11th and 60% for class 12th.
So, if you will prepare only for class 12th, you will be able to score around 120 marks in the exam. But to score good marks, you should prepare class 11th class as well.

Hello,
You just need to OBC certificate for proof that you belong to this particular category and in general you need recent photo, signature and application fee.

Hello Rahul,
JEE exam is only for admission to NITs and central funded university and if you have not crossed the cutoff then you can't get admission in type of colleges but for admission in other colleges you have to appear in the exams organized by these colleges.