Hello Aspirant,  The scope of Automobile diploma is good. If you learned all the things and studied well then it doesn't matter whether you have done it from government or from private Institute. This field requires lot of dedication and hard work to learn profession and achieve the success. The career option is very creative and fast paced. 

So many companies recruit automobile diploma holder. 

I hope this will help you. 

Hello aspirant,, there are lot of jon opportunities in automobile industry.

1. GOVERNMENT:- R.T.O. department is where automobile diploma & degree is considered first. Study for AMVI post get hired as a AMVI after some years of promotion you will be RTO officer.Indian Railways also have few departments where diploma holders are also considered.
2. Private sectors:- If you have a good technical experience in automotive sector which you can get from dealerships.

Hope it helps!!!