S. 263 : Commissioner-Revision of orders prejudicial to revenue-Real estate business-Income from house property-Value of unsold flats as stock-in-trade-Two possible views-Not erroneous-Business expenditure-Details filed before Assessing Officer and expenses allowed-Order is not erroneous-Revision invalid-Interest on tax deducted at source-Failure by Assessing Officer to carry out necessary inquiry-Order erroneous and prejudicial to interests of revenue-Revision is justified [S.23(1)(a), 40(a)(ia)]