If the birth was registered without name, you can notify any name subsequently, as provided under the provisions of section 14 of the Registration of Births and Deaths Act, which reads as follows:
"14. Where the birth of any child has been registered without a name, the parent or guardian of such child shall within the prescribed period give information regarding the name of the child to the registrar either orally or in writing and thereupon the Registrar shall enter such a name in the register and initial and date the entry."
However, if the name was also got registered, section 15 of the said Act provides for correction or cancellation of entry in the register of births and deaths, which reads as follows:
"15. If it is proved to the satisfaction of the Registrar that any entry of a birth or death in any register kept by him under this Act is erroneous in form or substance, or has been fraudulently or improperly made, he may, subject to such rules as may be made by the State Government with respect to the conditions on which and the circumstances in which such entries may be corrected or cancelled, correct the error or cancel the entry by suitable entry in the margin, without any alteration of the original entry, and shall sign the marginal entry and add thereto the date of the correction or cancellation."
HOWEVER, you may have to verify from the rules made by the Andhra Government made on these issues under the said Act, about the period within which that has to be got done.