You can attach additional affidavit ; it can be from your patents or someone close. Get it notarized before submission of its copy.

AFFIDAVIT OF BIRTH OF [APPLICANT’S FIRSTNAME MIDDLENAME LASTNAME]

1. My name is [first, middle and last name of the person providing the affidavit] and I am national of [country of citizenship].
2. I was born on [date of birth – Month Day, Year] in [place of birth - City, State, Country] and I currently reside in [place of current residence – Address, City, State, Country].
3. I have direct knowledge of the birth of [applicant’s name – first, middle, last] as I am [his] [her] [deskription of the relationship between the author and the applicant – father, mother, uncle, aunt, older sibling, etc. Note: the author must have personal knowledge of the birth. ].
4. [Applicant first, middle last names] was born on [date of birth – Month Day, Year] at [place of birth – name of hospital, deskription of home, etc.] located in [place of birth – City, State, Country].
5. [Applicant first, middle last names]’s biological parents are [mother’s first, middle and last name], the mother, and [father’s first, middle and last name], the father.
6. This Affidavit of Birth is being submitted to attest to the facts of the birth described herein because [the birth was registered late] [the birth was not registered late] [the birth certificate is not available].
7. I declare under penalty of perjury that the above is true and correct statement.

_____[First Middle Last Name of Author]____ _______________________
(signature)


DONE THIS THE ____ DAY OF _____________ 20__,

SWORN TO AND SUBSCRIBED BEFORE ME, THE UNDERSIGNED AUTHORITY ON THIS ___ DAY OF _______________ 20__.

Can't you get one from your municipality in Nepal? It shouldn't be very difficult to make a new one.

I Had same situation, The new dated birth certificate they do not approve. I have asked school and they send me a letter saying according to our record his DOB is ... on school letter pad. It approved. Good Luck.

Good news is coming

Thank you all for the responses.
@Nepal08 , so I asked around my friends circle who had green card earlier and they told me we can get Birth Verification from Ward office and I got the same one but not sure why USCIS issued RFE.
‘
@maxpayne thank you for detailed one.

@gaulejetho thank you.