R.90 of Order 21 of the Code of Civil Procedure, 1908 deals with -

Order XXI Rule 90 CPC allows a sale in execution to be set aside only for material irregularity or fraud in publishing or conducting the sale that causes substantial injury, so it deals with "Pre-sale illegalities committed in the execution", that is, illegalities in the execution process up to and at the sale. It does not deal with "Post-sale irregularities causing substantial injury to judgment debtor".