Court allows rectification of a sale deed under S.31 of the Specific Relief Act despite previous execution, addressing mutual mistake.

1. This is a second appeal by the defendants 5 and 6 to an action for rectification of a certain mistake which crept in the deed of sale in favour of the plaintiff. The facts leading to this appeal are that the plaintiff had purchased 2 bighas and odd of land of plot No. 418 having an area of 9 bighas 3 kathas and odd. Before purchase he was in possession of this very property as a mortgagee. The vendors of the plaintiff would not, however, register the document in his favour and he had therefore, to take recourse to compulsory registration of the document. In the meanwhile, what happened was that the vendors had passed on the property to some other persons by way of sale, namely, defendants 2 and 3 and thereafter the defendants sold to the present appellants, defendants 5 and 6, who are father and son.
Thereafter there was a suit by the plaintiff for declaration of title and recovery of possession in which all these defendants were made parties. The suit was fought up to the High Court and the plaintiff's decree for recovery of possession was upheld by this Court also. There was execution of the decree and the decree was executed by giving the plaintiff possession over the suit land. After all this had been done, the plaintiff woke up to the situation that the plot number which was mentioned in the sale deed was wrongly mentioned, namely, that in place of plot No. 435, plot No. 418 was mentioned. Thereafter he brought the present suit for rectification of this mistake in the instrument and consequential relief was also asked for in the shape of rectifying that mistake in all the proceedings taken thereafter, namely, the plaint, the decree and the execution petition. The first court dismissed the suit. On appeal, the lower appellate court, however, decreed the plaintiff's suit in the following terms :
"Ordered that the dag No. 418 in the sale deed (Ext. 2) in favour of the plaintiff be corrected as dag No. 435 and the judgments and decrees and plaint of T. S. 74 of 1945 be accordingly corrected and the Execution petition of Execution Case No. 25 of 1950 be also corrected. Ordered also that the plaintiff do get khas possession of the suit land on the strength of the corrected decrees in T. S. 74 of 1945 and the two appeals thereon. The original suit is thus decreed on contest with cost."
It is against this decree that the present appeal has been filed. The case of the defendants - appellants also was that they had purchased plot No. 418 but they contested the present suit of the plaintiff on the ground that the suit was not maintainable after the plaintiff had taken out execution of the decree in respect of plot No. 418 and of which he was given possession. It is also submitted that S.31 of the Specific Relief Act has no application. The last submission made is that the suit was barred by the provisions of O. 2 R. 2 of the C. P. C. I shall take up the point about the maintainability of the suit and the non - application of S. 31 of the Specific Relief Act together.

2. S.31 of the Specific Relief Act has to be read :
''When, through fraud or a mutual mistake of the parties, a contract or other instrument in writing does not truly express their intention, either party, or his representative in interest, may institute a suit to have the instrument rectified; and if the Court finds it clearly proved that there has been fraud or mistake in framing the instrument, and ascertain the real intention of the parties in executing the same, the Court may in its discretion rectify the instrument so as to express that intention, so far as this can be done without prejudice to rights acquired by third persons in good faith and for value."
This section, therefore, perm