A revised return of income can be filed in a situation, where an assessee discovers an omission or wrong statement made in the original return of income. It is a settled position of law that an assessee is entitled to revise its return of income within the time allowed under the provisions of sub-section (5) of section 139 of the Income-tax Act, 1961 . Once a revised return of income is filed, the natural consequence is that the original return of income is effaced or obliterated for all purposes, and it is not open to the Assessing Officer to advert to the original return of income.It is the settled position of law that in a case where the assessee filed a return of loss within the prescribed time under section 139(1) of the Act, there is no bar under the provisions of the Act to claim higher loss during the course of assessment proceedings nor are there any fetters on the Assessing Officer to allow such higher loss. The provisions of section 80 of the Act permit an assessee to carry forward loss and seek its set off under section 72(1) or (2) or 74(1) except when the loss has not been determined in pursuance of a return of income filed in accordance with the provisions of sub-section (3) of section 139 . There is no bar to claim higher depreciation during course of assessment proceedings .  That once a particular asset, forms a part of particular block of assets in respect of depreciation was allowed, even when that particular asset is not used in the relevant assessment year, depreciation on that particular block of asset on the written down value of that particular block of asset in which this asset falls is still allowable. There was no finding by the Assessing Officer that the block of asset, in which the plant and machinery leased to the Singapore company fell, has ceased to exist or there was a surplus in the block of assets in that particular block of assets and, therefore, since it was indisputable that no consideration was received by the assessee on cessation of the ownership rights over the plant and machinery, the question of deduction from the opening value of that block of assets in terms of section 43(6)(c)(i)(A) did not arise. Even if, the assessee ceased to be owner of that particular asset the written down value of that particular block of assets was not required to be reduced. That the fact that the assessee itself had reduced the written down value of the assets from the opening written down value of block of assets in the return of income, was not a bar to claim the higher depreciation during the course of assessment proceedings. That the question whether the loss arising on sale of shares of the Singapore company to its wholly owned foreign subsidiary company could be allowed as a business loss, became infructuous . (AY. 2016-17)