For both the fields you have mentioned, you need to go for the 10+2 course with the Physics, Chemistry and Mathematics. After your 10+2, you can go for the course of BSc Physics if you want to go for Astronomy. After that you can apply for the IIT JAM examination and can pursue the course of MSc Astronomy from IIT Indore or you can give JEST/TIFR examination for IUCAA & TIFR.

Now if you want to go for the Aerospace Engineering, then you have to go for the Entrance examination of JEE MAINS & JEE ADVANCED examination and you can take admission in IIT, NIT or other colleges. The best choice for the Aerospace Engineering will be the IIST as after your BTech if you have good score then you will get placed at ISRO.

To know more about Aerospace Engineering, visit the link below:

https://www.careers360.com/courses/aerospace-engineering-course

To know more about Astronomy, visit the link below:

https://www.careers360.com/courses/astronomy-course

I hope this answer helps.  All the very best for your future endeavors!

Greetings!

Aerospace Engineering is offer in variety of colleges. The basic eligibility criteria is that you must have secured minimum 50% in class10 and further you should pursue a stream which includes Physics and maths as a subject in class12 and secured minimum 50% in that also. If you are targeting top colleges for this course, then you should prepare for JEE main and advanced.

For more information about this field, visit-

https://www.careers360.com/courses/aerospace-engineering-course

Hope this will help you.