I have booked a flat in bangalore and I following query.

Q: I have paid a cheque for 20% of the total cost as downpayment, to the builder "ABC Constructions".The flat is part of a JV project between the landowner Mr.X and the promoter/builder Mr.Y of ABC constructions.

What I understand is that, the following things should have happened before the ABC constructions go for a sale agreement (for any of the flats owned by them) with a buyer.

1).There should be a Partnership Deed/Agreement between Mr.X and ABC Constructions (not with Mr.Y as an individual) in which it should be clearly mentioned that the land in question has been contributed to ABC constructions by Mr.X and so ABC constructions can make a sale agreement with the prospective buyer for any of the flats owned by them in that land.

2). A general Power of Attorney should have been given to ABC Constructions (and not to Mr.Y as an individual) that they can act as the land owner while signing a sale agreement with a buyer.

My qn is that,
1). if Mr.X has either signed a Partnership deed with some "EFG Constructions" which Mr.Y claims as a sister concern or group company of "ABC Constructions", will that be a valid agreement?

2). also if the Power of Attorney has been either given to Mr.Y or to "EFG Constructions", can the "ABC construction" sign a Sale deed with a buyer?

Can anyone please clarify. If something is not clear,please let me know, I shall explain again.
Thanks,