Diploma

The eligibility criteria of Graduate Marine Engineering (GME) is given below.
Eligibility : BE or B.Tech (Mechanical or Naval Arch) from AICTE approved college/university with minimum 50% marks and at least 60% in English in either 10th or 10+2. Fluency in written and spoken English is expected.
So from above Diploma Mechanical engineering students are not eligible for this course.

Hello Iqubal, these are thoughts which naturally come to mind after one gets a job after completion of the Diploma in engineering. But unfortunately, in practice, this is not available. UGC has made policy that no university can offer professional courses via distance education mode. However you have other option. You can do AMIE. This is equivalent to graduation in engineering for all practical purposes. My sincere advice to you is to follow this path to get your graduation. Best wishes to you.

The eligibility criteria of NDA is class 12th, So Diploma engineering students are not eligible for NDA.

Please write about the exam name for better response.