Zerodha requires you to either have an existing demat account (just buy in delivery is possible) or open a new one with IL&FS with whom they have a tie up (you can both buy and sell with IL&FS).The brokerage is 0.01% intraday or 0.1% delivery or Rs 20 per trade whichever is lower. There is a 400 Rs. per year AMC with IL&FS. and it costs Rs. 15 per ISIN sale.I'm a zerodha customer since Dec 2010.