Power of Attorney

Hello, I have a property in Hyderabad jointly owned by me and my wife and we are currently residing in UK and are citizens of UK with Overseas Citizen of India cards. We have decided to sell the property and wanted to understand the GPA process applicable to Telangana State. As the property is jointly owned by 2 of us and we can't give GPA to one person who can be blood relative, is it possible to have 2 GPA's one on my behalf and i will make by Sister as the GPA and can my wife make her brother as GPA and both can be present during the registration. We will get the GPA signed by Indian Embassy in UK and send it across to Hyderabad and during the validation / adjudication of these GPA's in Hyderabad would the charges be nominal Rs.1000? or would it still attract 1% of the property value? I would like to avoid unnecessary validation fee in India again as we will incur expenses to get the GPA process completed in UK at Indian Embassy. Appreciate your early response and clear process if the above stated one is wrong. Thanks in Advance for you help and valuable time. Regards Sumit