Hi,
Aeronautical engineering is upcoming sector in India,  which has immense potential and career opportunities after in government sector for  masters degrees or btech students who clear gate exam ( after graduating). If you are really interested and passionate in aeronautical engineering then go for it,  if you think you can go computer science then do not opt aeronautical.
After completing btech in cse, you cannot do master in aeronautical.  There is only once probability possible when you clear gate in aerospace subject after completing btech cse.