If you have interest and passion for Aircraft maintenance field then there is no reason as to why you can not pursue it. Generally people get success and rise in their interest areas because then only with that mindset, they can work hard to achieve it.
As regards the scope of job in our country as on today, there is tough and cut throat competition in every area where a prospective career is anticipated.
For example, if a student wants that he should get an opportunity of the job through campus recruitment then he should first fare well in the exam for the admission to a good institute and then he has to be in the top rankers there to be selected in campus recruitment mode. So the point is that one has to be in the list of scoring students to get instant success.
So, if your passion is for Aircraft maintenance area then you have to work hard and do the required efforts to enter that field. There are two ways to enter there. One is get admission in Aeronautical Engineering and then after completing it, apply in the aviation sector whenever posts are advertised. Another option is to go for some select diploma course which may enable you to enter there albeit at a lower level. Do not worry for that as with persistent hard work people rise from a small position to quite big levels. Most of the jobs in Aircraft maintenance are related to Mechanical and Electrical disciplines.
The aviation industry in our country is already flying in high colours and due to ever-increasing passenger strength it is poised to prosper further. The dynamic fare system has made it very lucrative even for the middle class people who are also trying to use it ones in a year during the lean fare period. The employees of companies and corporates are being sent by it to save precious time to increase the productivity.
Seeing this scenario, I believe that there are good prospects in this field and you should wholeheartedly pursue it.
Knowledge is power.