Hey.

According to the NEET PG 2019 eligibility criteria, you need to have a MBBS degree or provisional MBBS degree. Along with this you  also need to have completed or likely to complete 12 months mandatory rotatory internship on or before March 31, 2019.

You also need to have a permanent or provisional registration certificate of MBBS qualification issued by Medical Council of India any State Medical Council.

Considering this, you do not seem to eligible for NEET PG after completion of a medical diploma as the provisions related to the MBBS degree, Internship, registration certificate are not fulfilled.

Best of luck!