For undergraduate courses in Aerospace Engineering, you generally have to pass national entrance exams like the JEE Main and Advanced in India. These tests evaluate your understanding in areas such as Physics, Chemistry, and Mathematics, and are a stepping stone to premier engineering colleges like IITs, NITs, and other institutions. Getting a good rank in these tests is essential to getting admission into the preferred institution.
For postgraduate Aerospace Engineering courses, there are typically exams such as GATE (Graduateinders Aptitude Test in Engineering). GATE tests your knowledge of fundamental engineering topics and is widely used for entry into the IITs, NITs, and other engineering universities that offer master's degrees. Some universities might also have a particular entrance test or selection procedure. It's best to look up the requirements for each university so you know what to expect.