No marriage certificate for father mother deceased

[gamma50g]

Im trying to get a Green Card for my father.

He does not have a marriage certificate as it was not necessary to register Indian marriages when he got married in early1970s. From what I understood, marriage certificate is a necessity to prove my relationship with him.

My mother passed away a few years back. They dont give marriage certificage for deceased spouse. Neither is there an non availablity of marriage certificate like in birth certificate.

He has my mother's Death Certificate, their wedding inviation, wedding photos. Moreover my mothers passport and aadhar card lists him as spouse.

I saw a lot of people had queried regarding this, but no one came back to report how they tackled this issue. If anyone has been or is in the same boat as me, please reach out and let me know how did you solve this issue.

What documents would be proof in such a case?

[ember]

I have not been in your situation so please take this advice with a grain of salt (it might be wrong). I would send in all the evidence you mentioned, plus records that show that he is your father (your school records, health records, bank records, etc.), plus your mom's documents that show he was her husband (passport notation, bank records, death cert., etc.), plus maybe a DNA test. Also you can send in an affidavit by him confirming the marriage and that you were born in wedlock, plus the visa reciprocity.