JNTUH - Jawaharlal Nehru Technological University, Hyderabad

Hello Vikram,
JNTU is a public funded University and it doesn't have any management quota. Hence, you cannot get admission here from management quota seats.
You can check the below mentioned link:
http://www.jntuh.ac.in/new/

I don't think it is possible. but not sure.

You need to get a rank around 1600 to get into JNTU. But, if you need a good branch even, you must surely get a rank below 1000. Make an analysis of previously asked questions on how the weightage of marks is, from each chapter. Now, make a preferential order of topics so that you can get maximum of marks. Be thorough with your academic textbooks. Finally, attempt some mock test papers so that you will get an idea of attempting the EAMCET paper effectively.

No, Seat will be allotted on the basis of rank you get in EAMCET.

You can get an admission in to the course on which you have done your diploma. So the scope of better career will be there for you. It will help you for better placement as well.