1. Have you cancelled the POA you had issued to some one in India by sending him a registered letter?
2. If yes, you are required to notified the said fact of cancellation to the public in general by published it in two Newspapers, one being in vernacular.
3. If the POA holder has still sold the said property to the buyer then lodge a police complaint against the POA holder for cheating you.
4. Thereafter file a declaratory suit praying for a declaration that the said registration of deed for transferring your property is invalid since you had already cancelled your POA and praying for a direction upon the Registrar to cancel the said Registration.