Engineering

https://www.shiksha.com/b-tech/ranking/top-engineering-colleges-in-india/44-2-0-0-0
Here is a link where you will get the list of top colleges. Kindly visit this link.
Good luck.

I don't think so. There is an age limit for engineering since it is an undergraduate degree.

https://www.shiksha.com/b-tech/resources/upsee-college-predictor
Kindly visit this link.

No, you cannot get admission here without GATE scores. For getting admission here, you have to qualify GATE with good marks.
Check https://www.shiksha.com/engineering/course/m-tech-in-excavation-engineering-visvesvaraya-national-institute-of-technology-nagpur-297771 for details.
Good luck.

Yes, you may add computer science marks for best four subjects.
But your best fours must include English and mathematics in the first place.

Yes, you can get JSS Noida very easily and even any of the branches in that college without any problem. You can get it in the first round, according to the previous year's scenario.

Hello Mukesh,
You can visit the given link for top engineering colleges in Bangalore.
https://googleweblight.com/i?u=https://www.shiksha.com/b-tech/ranking/top-engineering-colleges-in-Bangalore/44-2-0-278-0&hl=en-IN
And you can find also another link for more colleges.
https://googleweblight.com/i?u=h

Getting CSE branch at this rank is quite difficult because this is the branch which gets filled very fast. Moreover, only in government colleges, there is SC quota. Other than that, there would not be any college that has SC quota.

Yes, you may not count maths in best four subjects.

The admissions into integrated M.Tech course in VIT are based on your score in 12th.