As per your query it is understood that you need information regarding the apartment in gram panchayat in Telangana.
The building in which you are buying a flat at 5th floor is approved for only G+2 so far. It means that builder is now taking a permission for increasing the height in it from the Directorate of town and country planning (DTCP) or Urban Development Authority (UDA) as the case may be in Bachupally Mandal which actually falls under Greater Hyderabad Municipal Corporation (GHMC).
The Panchayat can give approval only for G+2 levels. Please find from your builder about it and ask him to show the application form for the new construction or additional construction. Please note that there is a specific Building Regularization Scheme (BRS) in Telangana state under which one has to apply for any additional construction and pay some fee also. In fact, in the Govt of Telangana site in internet there are application form and calculators provided to calculate the fee for this additional construction. It is a very important step and if builder is not complying with it then I am afraid you will be taking a risk and once builder hands over this to you then the whole responsibility of paying this fee and penalty will be on your head. In extreme cases the local administration can take a view for demolition of unauthorized structures. It has happened at many places where builders are not complying with the existing rules and simply cheating the gullible public.
If anybody wants to go for deviations from the approved plans and want to construct more than what is approved, one has to get permission from Building Regularisation Scheme (BRS) in Telangana state under which one has to apply for any additional construction and pay a fee as per the pertaining rules and regulations.
What I will suggest is talk to the other owners or perspective owners of these flats and take up the matter with the builder collectively. Pressurize him for taking up the permission and payment of the requisite fee. Today the atmosphere in our country is changing and is in flavor of the consumer. You can also collectively threaten him for complaint in case he does not get the things properly approved.
Hope it helps!