Challenge of Sale Deed

All the legal heirs of your uncle have an equal rights over his property. You paid amount is immeterial here.

Means registered sale deed is no value here?

( 1 ) Since your uncle had sold his self a quired property to you by registered sale deed in their lifetime  so your another uncle can't  claim any share/right over it.

( 2 ) your añother uncle may claim their share/right over FD's of your deceased uncle if they get succession  certificate from competent  court.

My concern is that the consideration cheques value 40% of total property value couldn’t be deposited by him before his death though 60% was paid in cash. And as per apex court judgment, sale deed is void if sale consideration is not paid.

Your uncle's heirs has to execute sale deed to complete the sale as they are heirs but cannot claim right over sold  self acquired property of your deceased uncle .nominee for cash is only trustee they are heirs for money ,if they challenge defend in court .

Whether the document of Sale Deed contain covenent to the effect that you have paid full and final consideration amount, irrespective of the fact your uncle  i.e, the titleholder / vendor - since stated to have died before presentation of cheques, if so, you are ablsolute titleholder (owner) excluding other legal heirs of deceased, if any

You are the buyer of the property and the sale is absolute since there is registered dale deed too, but now the only thing is that the last payment is remaining that is how you have to pay .

The legal heirs of the your Uncle and aunt cannot claim a share from sold property which is already paid, now be careful for one thing only- how to pay the remaining amount ?  Since your uncle died intestate and you cannot pay him the balance amount directly so you will pay the amount to successors of your uncle. Forget about property that is sold, only the legal heirs of your uncle can claim share from  the balance amount and nothing else from the sold property. You should instantly deposit the amount in the district court with application addressed to court to disburse the balance amount for sale of property belonging to your uncle to its successors.

The court will hear the case of succession and shall release the amount to the successors.

That is the only way and legal way

Regarding the amount of your uncle in the bank , since you are nominee you should claim the amount as nominated successor of your uncle.

Your father and his brother are class I I legal heirs, hence they are entitled to acquire them