Mumbai municipalty
Non availablity of birth certificate

I was born in Aug1969, my birth was not registered. now for us non immigrant visa they require either birth certificate or Non availability certificate issued by Municipality. Mantralaya NOTIFICATION No. BDR 1099/896/C.R.173/F.W.3 point 13 (3) mentions

"If any particular event of birth or death is not found registered in the register or

the register is not available, the Registrar shall issue a non-availability certificate in Form No. 10 (a) or 10 (b), as case may be"

BUT MUNICIPALITY AUTHORITIES ARE NOT AWARE OF NON AVAILABILITY CERTIFICATE. CAN SOMEONE GIVE ME PROFORMA OF Form 10 (a) or 10 (b) issued by Mumbai Municipality.