Buying a Flat from LandOwner | GPA cancellation with Builder

Hi, I am planning to buy an apartment ... The Property is in Bangalore. There are following parties in the aprtment. Builder. He got GPA and has 56% share in the property. Landowner. They are a group of 8 brothers and have a combined share of 44% in the property The flat I am planning to buy is from the Landowner. Builder has already sold all his share of flats. Builder and Landowner have some differences over money (Land Owner needs to give some money to BUilder. Landowner is disagreeng to pay as Builder is yet to complete a part of the work ie, completion of a party hall and Generator setup in the same property). Now builder is not agreeing to come and sign the sale deed. Land Owner is planning to cancel the GPA. Land owner is planning to create a partition Deed and partion the flats from the Land owner share among themselves (8 Brothers and Sisters) After cancellation of GPA and after the partition Deed is created, I will buy the flat from one of the brother. In my sale deed these 8 Brothers and sisters will sign. My question is that enough for me to get Possession? In future can the builder pose me any threat over the Flat ? REgards, ABHIJIT