RVCE has Aerospace Engineering while Manipal has Aeronautical Engineering and both are not same. You must understand the difference and decide your preference and inclination. You may google it and you may also visit the below site …
Aerospace vs. Aeronautical – What’s the Difference?
Manipal has Aeronautical and Automobile Engineering Department which offers, BTech- Aeronautical and also BTech-Automobile. I’ll suggest not to go for specialization unless you are very sure about your inclination and in that case you may opt for BTech – Mechanical and subsequently you can take well informed decision. After BTech- Mechanical, you can always move to MTech- Aeronautical or MTech-Automobile or MTech-Aerospace as per your interest.
I am suggesting this as I feel many of students at this age of 18 to 20 years are not mature enough or exposed enough to decide based on the nature of subjects to be studied and/or nature of jobs available or possible after studies for these streams and they get influenced by reputation of institute/ placement statistics etc. You may see that most of the faculty members of these streams are also BTech in Mechanical and subsequently specialized in the particular area.