Hello aspirant

If you want to become scientist, you should select basic sciences in STD xii grade as per your liking

Mathematics and biology

Technology, Aeronautics, space scienctist, Data scientist, Earth scientist, physics, chemistry,

After xii you should select courses from following

B tech in Aerospace

BTech in Avionic Engineering

B tech + MS. Tech ( B tech in engineering)

physics +  M S in solid state physics, Astronomy, Earth system science

M tech in Electronics, Electrical, Mechanical and computer science.

PH D in relevant disciplines

Then you will have to do research work under guidence of seniors.