Hello,


If you want to become an aeronautical engineer then the first thing you must do is to pass your 12th with science stream(Physics,Chemistry,maths) from a recognised board.
Now, if you want to study in government colleges then you will have to give the JEE Mains Examination and you will have to get a good rank and make sure you get 75%+ in your 12th too.
Now, the best place where you can study is IITs, and if you want to get into them the you will have to crack JEE Advance examination.
There are many State Entrance Exams too.
Some major exams apart from JEE are :

• Delhi University Combined Entrance Examination(CEE)
• Hindustan University Entrance Test(HITSEE)
• The Indian Institute of Aeronautics Entrance Exam(IIA)
• SLIET Entrance Test(SET)
• IISAT Admission Test (IIST, Thiruvananthapuram)
• SRM Engineering Entrance Examination(SRM EEE )

I hope this helps.