Sizing, costing and breaking even on the RBI put spread

On 6 Oct 2026 the 13 Oct Nifty 22,750 put closed at 154.05 and the 22,450 put at 55.40; the lot size was 65. On 7 Oct they closed at 227.60 and 81.70. Assume 0.50 index points of slippage per option per transaction, paper capital ₹10,00,000 and a 1% risk budget, and the option charges of M01 · 1.7 (an illustrative brokerage of ₹20 per order; STT 0.15% of premium on sells; exchange 0.03553% of premium turnover; SEBI ₹10 per crore; stamp 0.003% on buys; GST 18% on brokerage, exchange and SEBI fees). Ignore slippage in the cost base (charges are on the bhavcopy prices). (a) Net debit in points. (b) Lots allowed by (3.23). (c) $1R$ in rupees. (d) Maximum profit at expiry in rupees and in R. (e) The break-even Nifty level at expiry. (f) The break-even win rate if every outcome were either full width or zero, ignoring costs. (g) Total charges for the round trip opened on 6 Oct and closed on 7 Oct. (h) Net P&L in rupees and in R, and the after-tax P&L at a 30% slab rate.