This is actually a tough situation to get a birth certificate of your parents who were born before 1957 (before independence) in Mumbai. Here are the steps that can help you obtain the certificate for them:
1. Visit the Municipal Corporation: Physically, you have to go to the office of the municipal corporation in your locality or the place where your parents were born. Request to search for their birth proof, which is a must to confirm that their original birth proof is not available. This will become a case of acquiring a non-availability of birth certificate. The search will go on, and the office will issue it.
2. Submit Necessary Documents: Now that you have to raise a request for NABC, compile papers in original to enclose with your application. These papers can be the following:
o Application form for NABC (available at the municipal office).
o Proof of your parents’ date and place of birth (e.g., school leaving certificates, old passports, or affidavits).
o Address proof of your parents.
o Government-issued ID proof of the applicant (you or your parents).
3. Affidavit: The documents to enclose will not be enough without an affidavit, which you may get from a sub-divisional magistrate or magistrate in your region. It's an oath that carries an authentic stamp of the gazette officer. So, it is accepted.
4. Attestation or Apostille: The affidavit without attestation or apostille stamp is invalid. So, it must be attested by the sub-divisional magistrate or district magistrate for validity.
5. Follow Up: This process may be a few weeks long. So, you need to physically visit the municipal court for updates on the requisite date.
Consulting professional services like Services 2 NRI can make this process seamless by ensuring all documentation is in place and expediting the process.