Engineering

Generally, the eligibility criteria for engineering institutes is at least 60% in class 12th. But it also depends on institutes if they offer any relaxation. This can be checked at the institute level.

It's not an exam, it's only a counselling process.

Following are your top options:
RTU
JECRC
SKIT
MBM.

CSE, IT, EC, and EE are the top branches in REAP.

No, it's not an exam, it's only a process.

IITs are best in class for aerospace engineering, apart from IITs, Indian Institute of Space Science and Technology, Thiruvananthapuram is the next best institute for this course. Other colleges you can look for are:
Park College of Engineering and Technology, Coimbatore
Lovely Professional University,
Punjab Engineering College, Chandigarh
Hindustan Institute of Technology and Science, Chennai
Indian Institute of Aeronautical Engineering, Dehradun.

Yes, Medi-Caps University is ranked among top engineering universities of India. Its among top -5 engineering institutes in M. P. Top IT companies visit the campus every year. For Computer Science branch, placements are almost 100%. If you are looking for CSE, then Medi-Caps is a good institute to join.

There is no doubt that IITs are best in class for aerospace engineering and apart from IITs Indian Institute of Space Science and Technology, Thiruvananthapuram is the next best institute for this course. Other colleges you can look for are:
Park College of Engineering and Technology, Coimbatore
Lovely Professional University,
Punjab Engineering College, Chandigarh
Hindustan Institute of Technology and Science, Chennai
Madras Institute of Technology, Chennai
Indian Institute of Aeronautical Engineering, Dehradun.

You have to get admission through management quota seats. Consult the college management and get your admission done.
All the best

It cannot be said that nanotechnology is better than CS and IT. As all the fields are good in their respective areas. It's just that nanotechnology is a new field and will be developing just like CS and IT.