Key Points: - The case involves a suit under O. 21, R. 63, Civil P. C. where a decree-holder sought to attach properties of the first defendant as belonging to the judgment-debtor [2000269650001]. - The first defendant pleaded that the debt due to the plaintiff was bogus and the decree was vitiated by fraud and collusion [2000269650001]. - The Subordinate Judge initially held that in a suit under O. 21, R. 63, Civil P. C., it is not open to the defendant to attack the decree or the debt [2000269650001]. - The High Court held that it is open to the defendant in such a suit to attack the decree or the debt on which it is based [2000269650001][2000269650002]. - When a decree-holder seeks to seize a petitioner's properties in execution of a decree, the petitioner is entitled to raise all available defences [2000269650002][2000269650003]. - A suit under O. 21, R. 63, Civil P. C. is essentially a litigation of a question of title, not merely a continuation of claim proceedings [2000269650002]. - A third person or stranger to a judgment whose rights are injuriously affected may show in a collateral proceeding that the judgment was procured through fraud or collusion [2000269650004]. - Under Section 44 of the Evidence Act, a petitioner may establish that a decree sought to be executed against them was obtained by fraud or collusion [2000269650004]. - The court noted that properties not belonging to judgment-debtors should not be proceeded against based on decrees obtained by fraud or collusion [2000269650004]. - The High Court set aside the findings of the Subordinate Judge on additional issues and allowed the Civil Revision Petition [2000269650008].

Whether in a suit under O. 21, R. 63, Civil P. C., the defendant can attack the decree or the debt on which it is based?