. . . "Assessment procedure???: 16.1 Return of income (S. 139)???: (i) The first proviso to this S. 139(I) provides that a person, other than a company or a firm whose income is not chargeable to income tax, should file the return of income if his expenditure on consumption of electricity is Rs.50000 or more or if he fulfils any one of the six criteria." . .