Surcharge on income tax: prescribed surcharges increase tax liabilities and adjust computations for agricultural income and special incomes. The provision prescribes income tax rates for the assessment year and mandates that tax determined under the First Schedule be increased by applicable surcharges across categories: regular tax, special chapters and sections, withholding and collection obligations, and advance tax. Net agricultural income above prescribed minima is aggregated with total income for tax computation using a specified aggregation and subtraction method, after which rebates are applied and the resultant tax increased by surcharge. Distinct surcharge treatments are specified for classes of taxpayers and certain special incomes, with limited exemptions for foreign companies; key terms are defined for section application.