Aeronautical Engineering is the science involved with the study, design, and manufacture of flight-capable machines, or the techniques of operating aircraft. It trains an engineer in designing, constructing, analyzing and testing of commercial or military aircrafts, missiles, and spacecrafts.

It covers subjects and disciplines like aerodynamics, avionics and propulsion among others. 

These are the course subjects you will study in this branch:

• Design & Dynamics of Autonomous
• Micro & Mini Air Vehicles
• Fluid-Structure Interactions
• High Speed Jets & Acoustics
• Intake Aerodynamics
• Missile Guidance and Control
• Structural Design & Optimization
• Transition and Turbulence
• Unmanned and Autonomous Air Vehicle

You should have PCM in your class 12th to apply for this Btech course.

You can check the complete information for aeronautical engineering here.

Good Luck.