If a birth certificate is not available or does not contain all of the necessary information, affidavits can be submitted instead. Information necessary on a birth certificate include the date of birth (registered within one year), the name of the individual, and the names of the parents, and the place of birth. If affidavits are necessary, one would need either a copy of the birth certificate that was issued, or a certificate of non-availability issued by the municipality where the birth took place.
The birth affidavits should be from persons with knowledge of one's birth, signed before a notary signifying that the affidavits have been sworn as to their accuracy. Often, people get the affidavits from their parents, but it doesn't have to be from them. Anyone, such as an aunt or uncle or a significantly older sibling, with knowledge of the birth can submit an affidavit. The affidavit should give the name of the affiant, state the relationship that the affiant has to the individual, address, names of parents, place of birth, and reason for giving the affidavit.
In addition to the two affidavits, one would also submit a self affidavit, indicating why the affidavits are being submitted instead of an acceptable birth certificate. Besides the birth affidavits and the self affidavit, one should also submit additional secondary evidence, such as school-leaving certificates, doctor or midwife certificates, etc.
http://www.murthy.com/misc_faq.html
Also,
• Submit any available secondary evidence of birth, such as church or school records.
• Submit a sworn (notarized) letter from you explaining the efforts you made to obtain both
church/school records AND the birth record from your home country.
• Submit a letter from the appropriate government authority confirming that birth records do not exist
or are not available, if you can get such a letter.
