Income-tax rate adjustments apply prior Act provisions to the assessment year with modified rates, surcharge, and loss set-off. The Act applies the prior Finance Act's income-tax provisions to the subsequent assessment year with specific substitutions: year references are updated, certain percentage figures in a subsection are altered, Part I of the First Schedule is replaced with revised rate tables and surcharge rules for individuals, cooperative societies, registered firms, local authorities and companies, and Part IV rule 9 is amended to prescribe the order and scope for carrying forward and setting off agricultural losses from specified prior years.