Hello aspirant

For admission to Government Engineering college, you must appear for entrance exam for the course. There are two ways , one is through Jee main and other CET.

Other necessary requirement is you should have scored Minimum 50% marks in PCM (50%  for general Category and 45% for SC/ St category)

If you have cleared your STD xii privately . Then you must be having two mark sheets.  You don't have to worry , you should present your both mark sheets . You are ex student do you will have to submit your gap Certificate also. If you are fit in requirements then you can get a seat .

Hey dear, you need to wait for you jee exam only then you can decide where you want to pursue your engineering. Since you are insisting for govt. Enguneering college so only when you clear jee exam than only you can enter any one of them. As far as private colleges are concerned you can take admission any time you want through management quota.