Stamp duty is charged on the higher of price and circle rate
Stamp duty is a state tax, commonly 5% to 7% of the consideration, with about 1% registration charge on top. The 6% used here is a representative combined national figure; Maharashtra charges 6% inside municipal limits plus a 1% metro cess, Karnataka 5% in Bengaluru, Delhi 6% for a man and 4% for a woman.
The part that catches buyers out is the base. Duty is charged on the higher of the actual price and the state's circle rate, sometimes called the guidance or ready reckoner value: the minimum value the state will accept for that locality. Buy below the circle rate and you still pay duty on the circle rate, and the difference can also be taxed as income in your hands. So the transfer-tax figure here is a floor, not a ceiling.
Several states charge women buyers one to two percentage points less, and a few offer a further concession for a joint purchase in a woman's name. That is a real saving of tens of thousands of rupees on a typical purchase, and it is not modelled here.
No mortgage insurance, but a margin requirement
Indian home loans carry no mortgage insurance. The Reserve Bank's margin requirement does the equivalent work: lenders must keep 10% to 25% of the property value out of the loan depending on the ticket size, which is why the deposit here opens at 20%.
Municipal property tax is assessed on an annual rateable value rather than on the price, and the method differs by city: unit area in Delhi, capital value in Mumbai, annual rental value elsewhere. The 0.15% of price shown is a rough national equivalent, not a rate any municipal corporation publishes.