As per indian law what is the valid document for age proof

As per Indian Law the valid document for age proof are all the instruments i.e. (Government Photo Id's containing age) and if in case you do not possess the same, you shall prepare an Affidavit from a law professional and get it attested and notarised from a valid notary licence holder and on this basis you can also create the other required instruments for age proof or on urgent basis the same can be used in place of birth certificate.

S.S.L.C MARKS CARD. IF NO SSLC MARKS CARD ADHAAR CARD. IF NO AADHAR CARD OR SSLC MARKSCARD, INDIAN VOTER IDENTITY CARD.

I have a doubt about the authentication of the said documents, usually documents such as voter id, aadhar card people do not provide, resulting mismatch on their dob, and with all respect we all know affidavit can be created by anyone and even court does not consider its authentication. I am asking this question because i am into adoption program, and documents whivh parents provides always have such issues