You need to be a BE/B.Tech. in Aerospace Engineering. There are also diploma courses, which
you can pursue after 10+2 but you will need to complete your degree before you get a good job. After graduation, you could pursue an M.Tech. or Ph.D. in aeronautics. Then there are exams conducted by the AeSI (Aeronautical Society Of India). This exam is considered equivalent to a Bachelor's degree in aerospace engineering.
You will study subjects like Principles of Flight, Aerodynamics, Aircraft structure, Propulsion, Avionics, Electronics, Metrology, as well as Airworthiness Regulations and Air Traffic Control.
You will then have to choose an area of specialisation namely, aerodynamics, propulsion, structures, navigation and control, instrumentation and communication, etc. You could also specialise in aerospace products viz., commercial transport, military fighter jets, helicopters, spacecrafts, missiles or rockets.