NIT

Yes, you are eligible for next year JEE exam.J EE has nothing to do with your past years. Although you will have only one attempt for JEE Advanced and two for JEE Main.

If you are quite specific about the branch then go for NIT. There are cases when you have interest in particular branch or subjects then don't hesitate to opt for NIT and rejecting IIT. I had to face the same situation 3 years back and i don't regret my decision at all.
Moreover, if you don't have any such particular interest then you can obviously go for IIT. It's a huge tag after all.
Be careful as it is not an easy task to go 4 years with subjects that do not interest you.
Good luck

Hello Abhishek,
For admission in any NIT, you need to take JEE Mains only. There is no other way out, However, if you are studying in B.Tech first year then concentrate on your B.Tech course. However, if you want to switch then prepare well for JEE Mains.

Yes, you can, but you need to qualify JEE Mains and Advanced exam. You need to secure a rank under 2000.

Hello Prince,
As you have got 170 marks in JEE Mains paper-2, the admission will be based upon counselling rounds conducted by various NIT's. The cut-off score for this exam is not yet declared by the responsible authorities.

There is some possibility of getting NIT. But, for good NIT, you have to compromise for branch. Rank goes up to 30000 for general category for NITs. So, keep good hopes.

If it is your common merit rank, then you will get admission in very good NIT with CSE.

To get admission in b.tech programs offered by various NIT's, cutoff is varied, depending upon the category to which one belongs. But, if we look upon top NIT's of India, the cutoff rank declared by them mostly ranges b/w 26k to 70k.

Mechanical engineering is basically the engineering related to machines, their working principal, mechanisms, about the different materials used and other designing parts of various machines.

First of all, congratulations.
You got a decent rank. You will get CSE/IT in top NITs. The average package of CSE in top 5 NITs are above Rs. 5 lakhs p.a. You should join IIIT, Allahabad, as it has very good coding culture and placement is also excellent there.