Which branch of engineering should I choose to pursue further education in astronautical engineering?

Hi Seetha!! I'm a student in 12th grade with physics, chemistry, math and computers as my core subjects. I'm residing in India right now and would like to pursue Bachelors in Aerospace Engineering. However, Bachelor's in Aerospace isn't available in all colleges/universities here. There are other options like Mechanical, Electrical, Chemical and so on.

Which branch do you recommend me to take up in case I don't get into Aerospace, to obtain Master and then PhD in Astronautical Engineering (Aerospace divided into aeronautical and astronautical, I want to choose Astronautical) and hence pursue a career in Astronautical Engineering?