India: two regimes and two cliff edges
India lets you choose. The new regime is the default and gives wider slabs, a 75,000 rupee standard deduction and a larger section 87A rebate, but allows none of the old regime's deductions. The old regime has narrower slabs and a smaller standard deduction, but lets you claim HRA, section 80C, 80D and home-loan interest. Which wins depends entirely on what you claim, so the calculator models both.
Two cliff edges make Indian tax unusual, and both are softened by marginal relief rather than left as genuine cliffs. The section 87A rebate wipes out tax entirely up to a limit, and just above it relief caps your tax at the amount by which your income exceeds the limit, so crossing the line by 10,000 rupees costs you roughly 10,000 rupees and not the full slab tax. Surcharge works the same way at each of its thresholds. On top of everything sits a flat 4% health and education cess.
Standard deduction 75,000, leaving 14,25,000 of taxable income. Slab tax plus the 4% cess: 97,500.
EPF at 12% of basic salary, taken as half of gross: 90,000 into your own provident fund. Your employer contributes the same again.
Take-home: 13,12,500 a year, 1,09,375 a month. Professional tax is a state levy of up to 2,500 a year, so pick your state if it charges one.