Optional tax regime expansion: individuals and specified entities may opt into revised slab-rate taxation with restricted deductions. The amendment inserts a new sub section providing an optional tax regime that computes income-tax for eligible persons under a prescribed slab-rate table for specified assessment years, and mandates that total income under this regime be computed without a list of enumerated exemptions and deductions, subject to limited exceptions; it also prescribes transitional adjustment to written down value for depreciation and preserves an exercise/withdrawal mechanism for the option with specific procedural conditions and modifications for IFSC Units.