Brokerage at Zerodha will be a maximum of Rs. 20 per executed order irrespective of the size of your order.
[(0.01% for Intraday/Futures & 0.1% for Delivery) or Rs. 20 whichever is lower.]

Stamp Duty is charged at 0.01% or Rs. 50 per contract note - whichever is lower.
*Stamp duty is charged according to the Karnataka Stamp Duty Act and is not included in the brokerage calculator.