Engineering

Sorry, but no college (government) will offer admission With ECE and CSE branch. Moreover, try for private colleges like LPU, CU or Amity.

Yes, you can join some colleges but some colleges set the criteria that they can take students only who got above 70% marks in class 12th. But some colleges will take the students who have above 60 percent marks too.

Yes, you are likely to get if not in Hyderabad then may be in IIIT-Allahabad.

You can check the college predictor for this . Moreover , with this rank , you can get CSE in all the NIT's . May be definitely with surathkal or Warangal ( if not trichy ) . Hence, you don't need to worry a lot . Moreover ,you can check the colleges below .
https://www.shiksha.com/b-tech/resources/j

Yes, you took a good decision. Though you might not have got any colleges through your JEE and COMEDK rankings, you took the perfect decision. Still, try for core branches such as CSE or ECE.
Best of luck.

Almost in all top NITs. Try to go for NIT-Trichy, Warangal or Surathakal according to their priority in JOSAA followed by Rourkela.

You can get admission but in not so good NIT. Moreover, if you are able to land up a good branch, it may compensate the name of a low rank NIT.

You have to do B.Tech in Civil which is of 4 years then you will get a B.Tech degree (Certificate). There are total 8 semesters in B.Tech, you have to clear all of them in 4 years.
Best of luck for your future.