Hi,My CTC is 25 L and Variable is 4.12 L. Variable is separate. Please suggest tax slab

Ans: The tax you save would depend on the deductions that you make (the old regime will lower taxable income for permissible deductions and thus have a lower tax to that extent). Most of these deductions are not available in the new tax regime.
If you claim no deductions other than standard deduction, the tax saving comes to about Rs 1 lakh under the new regime. If you claim Sec 80C and NPS, then new regime would be better by Rs 39,000

Ans: You will be in the 30%+surcharge tax slab.

Ans: New regime

Ans: Person should select tax regime based on eligible amount of deductions/exemptions under both tax regime. Usually when person is eligible for maximum of specified limit old tax regime is beneficial.

For e.g. if person is earning income from salary of Rs.15 lacs, eligible for deduction of Rs.1 lakh (say from HRA) and eligible for deduction for tax saver investment of Rs.1 lakh (say from LIC, PPF, Tax saver MF, Mediclaim etc). New tax regime is likely to reduce tax liability for FY 23-24.

However, if we change example and increase deduction from salary to Rs.1.5 lacs and deduction of tax saver investment to Rs.2.5 lacs, old tax regime is likely to beneficial for FY 2023-24.

You can compare tax liability at https://incometaxindia.gov.in/Pages/tools/115bac-tax-calculator-finance-bill-2023.aspx

Ans: Selection of tax regime depends of eligibility of amount of deduction and exemption. Considering income of 40lacs, when amount of deductions/exemption cross 7,75,000; old scheme is likely to be beneficial for the tax payer.

You can calculate tax liability, using advance income tax calculator available at following link:

https://eportal.incometax.gov.in/iec/foservices/#/TaxCalc/calculator