Alternative for Birth Certificate of I-130 Petitioner to prove Mother - Child relationship

[btnivas]

Hi

I filed I-130 to sponsor my mom and got an RFE requiring birth certificate to prove proof of relationship.  I do not have a birth certificate, hence submitted the non-availability certificate from local municipality and also two affidavits (from my uncle and aunt).  Still got an RFE for Birth Certificate to prove relationship.

What are my options?

Can I just go ahead and get a DNA test done for both myself and my mother?

Is there a format to obtain a Certificate from School?

Will a letter from Indian Embassy in the US containing my my birth information based on the old indian passport be acceptable?

Thanks for your responses.

BT