Don't complicate simple thing by over thinking.

Submit:
1. Morang hospital birth certificate (they might have provided you during your birth).
2. KTM issued birth certificate (make sure it is translated, it has clearly indicated your place of birth and attest it).
3. Your translated citizen card (nagarikta) which clearly shows your place of birth.
4. I wouldn't recommend submitting another birth certificate as it might cause problems.

Bottomline, be honest and transparent.