Circular No.621 – Income Tax In respect of incomes of all categories of taxpayers (corporate as well as non-corporate) liable to tax for the assessment year 1991-92, the rates of income-tax (including surcharge) have been specified in Part I of the First Schedule to the Act and are the same as those laid down in Part III of the First Schedule to the Finance Act, 1990 as modified by the Taxation Laws (Amendment) Act, 1991