Minimum percentage requirement for Aerospace Engineering is different at different universities and countries. Mostly, the universities demand students to have passed their 12th grade in science stream with physics, chemistry, and mathematics having a minimum of 60-75% aggregate marks. The criteria could be more strict based on competitive exams, and it can affect the cutoff even further. It's also worth noting entrance tests such as JEE (Joint Entrance Examination) in India or SAT/ACT scores elsewhere, which in many cases are a deciding factor in admission.
In addition to academic qualifications, universities can also look at other aspects like extracurricular activities, aptitude tests, and performance during interviews. Those with a solid foundation in mathematics and physics have an edge since these are the key subjects in Aerospace Engineering. The admission criteria, however, can differ quite a lot between institutions, so it is always best to verify with each university for the specific percentage requirements and any other prerequisites before applying.