what field and which type of college i should choose after 12 if mine interest is in astronomy i am very much interested to know about stars ,planets etc
see since your interest has in astronomy, you should take bachelors in astro physics or physics course in ug level, to become an astronomer phd degree is must, since astro physics is a part of physics, you may do bachelors in physics then you go for masters or phd course in astro physics, iisc bangalore is best for bachelors program, it offers 5 years bs-ms dual degree course in physics, it is a research oriented program and curriculum has wide variety compare to other local colleges.
admission is based on kvpy exam score/ jee main ,jee advance score /neet ug score basis . follow the below link to know in details,
You can take up B.Sc Physics or B.Sc Mathematics. You also can try AstroPhysics. B.Sc in Chemistry also helps for a career in Astronomy. If you want to take up Engineering then your go to branches should be Electronics and Communications Engineering, Electrics and Electronics Engineering and Computer Science. But a Master's degree will help you with better career opportunities.
If you are from 12th PCM background, you can go for btech in aeronautical engineering.
There are so many colleges for aeronautical engineering.
You can apply for both in private or government colleges and universities.
Hope this is helpful