Hi
Whilst attestation of GPA by Indian embassy/ Consulate is only to authenticate that the daughter in fact executed the GPA, the registration of GPA at Sub-Registrar office is mandatory in law.
In your case, it appears that the GPA has been registered at Sub-Registrar office by paying the requisite stamp duty and registration charges and thereafter the property has been transferred, technically, you are in compliance with law and hence no further action is required.
We also presume that you have made payment of sale consideration to the daughter which again should support your title .
However, for any reason, you doubt the authenticity of the GPA , then please ask the daughter to get the GPA attested by Indian Embassy.
Hope this information is useful.