GPA and Memorandum of deposit of Title Deeds

Hi Sir, 1. Part1 has registered a GPA on my dad name in Uppal (SRO) but the property is in Hyderabad (EAST) SRO office , Here Party1 is not in our blood relation . 2. He has taken a loan of rs 5000/- in 1990 and in turn he has done the Memorandum of deposit of title deeds in which he has mentioned that he has taken loan and for which he is depositing the original Sale deed Copy and link document with us on certain agreed interest percentage amount ( Interest percentage not mentioned) . 3. After 2 years in 1993 he did the GPA on my Dad name in Uppal (SRO) , we currently have the registered GPA document with fee payment receipt . The problem over here is we are unable to track the GPA online in Hyderabad (EAST) SRO for that property as it is registered in Uppal SRO office . Is it correct to register the GPA in any sub registrar office , If so then why it is not visible in the EC . We are planning to sell the property to my dad himself as the GPA is currently on his name only . We want to know how far the transaction would be valid .