I want to pursue Aeronautic Eng.But I Heard it is betr to do Mech Eng an thn do Mtec in Aero! Is it Possible?

Hi I Finished my 12th and interested in Aeronautic engg. But many say its better to do Mechanics First and then Do masters in Aero ! as it has more scope ! Is it possible ? If it is Wat shud we oppt for in Mechn 7th an 8th sem's Electives ? Which do u think is better doin Btec in aero or doin Btec in Mechn ? Plz Help Guys ? Thanks in Advance !