Engineering Scope

For ISRO, you'll have to clear GATE with very good score card. Otherwise, you can't get job in ISRO.

After the completion of degree in aeronautical engineering, you are eligible for not only in design & production of aircraft and spacecraft but also in turbine, high-speed trains (bullet trains), flying gadgets and turbine production & design. Some of the job profiles are as the following:
Thermal Design Engineer
Consultants
Mechanical Design Engineer
Aerospace Designer Checker
Graduate Engineer Trainees
Assistant Technical Officers
Some of the reputed recruiters of aeronautical engineering are as the following:
HAL
DRDO
ISRO
Air India
Indian Airlines
Helicopter Corporation of India
DRDL
NAL
ADE.

Yes, it's a good option but it will be better if you opt for Bachelor's for a good job.

No. There is nothing which can give you online Bachelor's in engineering. But, you can get your Bachelor's through AMIE via distance learning it's a B.Tech equivalent but some companies and colleges not accept Amie holder.

Hello Saravanan, The scope of aeronautical engineering encompasses all the subjects which are required for studying of an airborne object. It includes different subjects like metallurgy, structures, electrical, mechanical or avionics to study to a certain extent. Unfortunately, the job prospects in India are very less. Once you get job the salary is as good as any other engineer. Best wishes to you.

You should choose PCM, as you want to become mechanical engineer you must focus more on Mathematics as In Mechanical Engineering many subjects are numerical base.