Hey,

Candidates can apply to IISER by one of the following three channels-:
• KVYP Channel: kishore vaigyanik protsahan yojna
• JEE channel: Joint entrance examination 
• SCB channel: State and Central Board channel. Students who pass their 12 boards in science stream(PCM or PCB) with marks equal or above the cut off percentage in their respective boards are eligible to apply through SCB.

Aerospace engineering is the primary field of engineering concerned with the development of spacecraft and aircraft. It has two major branches -:
•Aeronautical engineering
•Astronautical engineering

To know more about this course, go to this link -:
https://www.careers360.com/aerospace-engineering-course

All the best!