Aerospace or aeronautical Engineering is mainly focused on manufacturing an aircraft. Designing and manufacturing to be precise. Its a great course for someone wants to improve their knowledge in the Aerospace technology. Lots of calculations are involved. When it comes employability this qualification has very little value.
Courses like mechanical or Electrical engineering covers a wide area of knowledge. Where as aerospace or aeronautical are very specific to air vehicles alone. Therefore your knowledge to be utilized, you must be employed in a manufacturing or designing company. But how many countries are producing Aircraft or designing Aircraft?
Aeronautical Engineering
There more than 80 percent of aeronautical engineers are unemployed in India. Where the rest of the 20 percent are employed in the fields got nothing to do with their qualification. I dont have the statistics for any other countries. Students of Pakistan Sri Lanka or Indonesia would suffer the same fate. The course opens no gates for migration since it is also hard to find jobs in the developed world.
If you wish to be employed and do a job related to Air vehicle engineering, Aircraft maintenance engineering course is the only option. Even in aircraft maintenance Engineering the employers trying restrict the amount of employees. Some of them employ unskilled and unqualified labors to perform maintenance task. In last decade though the Aviation field has expanded drastically, demand for aircraft mechanic did not show significant growth specially in south and east Asia.
In case of unemployment there are no business in aviation can be started with a low capital. No Aircraft engineering, aerospace nor aeronautical course modules have any business related subject in their academic curriculum.
If you are still determined to do Aerospace or aeronautical go ahead. If you are taking the lower risk by taking Aircraft maintenance course its worth looking at my article to know how the job environment will be.