bind on plaintiffs cannot be exceeded too. The question as to whether it is a collusive decree and the question as to whether the agreement to sell dated 31.12.1992, in favour of defendant No.2 is a concocted agreement cannot be gone into in view of the decree for specific performance passed in O.S.No.118/1993. If the decree for specific performance passed in O.S.No.118/1993 in favour of defendant No.2 has gone unchallenged, the plaintiffs cannot have recourse to Section 15(2)(a) of the Act and claim ownership over the suit schedule property. Had Akkayyamma died interstate, the plaintiffs would have acquired rights under Section 15(2)(a) at the exclusion of defendant No.1/husband. But the records clearly reveal that Akkayyamma, during her lifetime, executed an agreement in favour of defendant No.2 and defendant No.2 by instituting a suit for specific performance in O.S.No.118/1993, has succeeded in proving the due execution of the agreement. The decree for specific performance passed in O.S.No.118/1993 is enforced by defendant No.2 by filing Ex.P.No.56/2005. If the decree