How the calculation works on Rs 3,00,000 / month
At Rs 3,00,000 a month you're into top-tier salary territory, usually C-suite or specialist work, and into the 25% marginal band, where 25 paisa of each extra rupee goes to tax. That's Rs 36,00,000 a year. After the Rs 3,16,000 fixed amount plus 25% on the income above Rs 32,00,000, your tax is Rs 4,16,000 a year, or about Rs 34,667 a month. In FY 2025-26 the same salary paid Rs 4,66,000, so you're Rs 50,000 a year better off. Your effective rate is 11.56%, but the rate on anything extra is 25%.
That works out to roughly Rs 34,667 a month deducted from your gross, leaving you with Rs 2,65,333 take-home.
What changes if you're not salaried?
At this income the salaried route is clearly the lighter of the two ordinary options. A non-salaried filer on Rs 36,00,000 a year pays Rs 8,10,000, Rs 3,94,000 more than you, with their next rupee taxed at 40%. Registered IT export income is far lower than both, at 0.25% of proceeds, or Rs 9,000, which is why at this level how your income is classified is worth so much every year.