We are four legal heirs, my mother, I and two married sisters. My mother and I had entered into a sale agreement and signed the agreement (UN registered) and received an advance amount through cheque,      but my two married sisters due to family issues they are not ready to sign neither Sale agreement nor the Sale Deed.  The buyer was not ready to cancel the sale agreement; he forced us and issued a legal notice to get it signed by my sisters, needful.
      As per our expert lawyer’s suggestions from property. the club, I have replied to the notice informing about my inability to sell the property, as we four together are the joint owners and the possessors of the undivided share of the said schedule In the notice my lawyer stated that after receiving of the reply notice the agreement of sale will stands cancel. And also stated that we are ready to return the token amount.  But the buyer has not taken the token amount, he approached the court.  He succeeded to get the “Exparte Injunction Order”, and the next hearing date is 2^nd of April 2012.

      Even I along with my sisters (the other legal heirs) filed a suit for cancellation of agreement, and got the “Status quo order”  

    Will we win the case and the agreement will get cancelled or the purchaser will win the suit for specific performance? Kindly do the favor for me and give your valuable suggestions.

Your sister has to file suit for partition and seperate possession.  The sale already made by you is applicable to your share only.

Since he had no agreement with your sisters (co-owners) and you alone could not sell the whole property - he can at most specifically enforce the agreement insofar as it concerns you share i.e Specific Performance of a Part (Section 12). Which the Court in all probability would refuse -since the part left unperformed is half of the total property. He would have an option to seek specific performance without any rebate (as regards price) i.e he can choose to pay full amount and get only half a property, and even after getting half the property - he won't be able to seek joint possession with other co-owners, and can only ask for the partition.