Hello aspirant

It's a common problem. It can be solved with a simple affidavit. It should mention both the names of the person (your father) and should declare:

1. That both these names pertain to the same person
2. That it is true to your knowledge, and
3. That you're accountable for any discrepancies.

And you need to get the affidavit notarized by a first class magistrate.

Hope this helps. All the best.