JEE Main

You can apply for private or autonomous campuses all over India. For those colleges, NATA is not needed.

You need to give the NATA exam (preferably before the end of May) and then in the month of June-July apply for the admission process of DTE. If your NATA score and 12th percentage are really good then you might get into Sir J.J. college of Architecturing.
Admission to B.Arch. is done on the basis of valid score obtained in NATA/ JEE Main 2018.

Yes, you can expect a seat in any of the NITs. Warangal and Raipur are having more chances.

For mechanical branch it was around 500-1000 state merit rank. For comps it was around 1600-1800 and for IT elex ExTC it was around 3000-3500 till CAP2 with percentile of around 96. If you have patience then i will suggest to wait till CAP3 ie. Counselling round as cutoff there was around 6000 for comps and 11000 state merit rank for IT. So if you have less score then keep calm and wait till CAP3. You will easily get into the college you want.

It completely depends on your choice what you want to do in the future. B.Sc. Students mainly opt for higher studies, research whereas B.Tech students go for placement, startup, higher studies and MBA. Choose wisely what you want to do.

Sorry, these marks are comparatively lower than what is needed. For OBC , it's 100 required for getting into core branches of MITS Gwalior and around 80 for non-technical branches. Kindly try for ITM Gwalior, LNCT - Bhopal, GECU - Ujjain (if you need only govt., else not).
Best of luck.

Yes, there are full chances of getting CSE in NITs. You must have to participate in counselling of JEE. Only after counselling, we will get to know about fees concession.

Bro, I suggest you to take admission in any one of your nearest colleges. And do hard work in the computer field that is, learn programming languages and try to make projects based on them. After some time, you will get to know about how companies are doing their work.

With defense quota, you'll get non-technical branches such as instrumentation, manufacturing and automation , Control engineering being from outside Delhi.
If you are from Delhi, you'll likely to get either BIOTECH , CIVIL or MECHANICAL in second or third round.
Best of luck.

Sorry, but you will not be able to get into Nirma Unversity with these marks. Though the selection is dynamic and dependent upon the students applying for it and hence changes every year, still the cutoff for CSE/IT is around 2k and the least non-technical branches is around 80k.