I also have account with Sharekhan and they charge Rs.70/Lot in F&O, whereas it will come around Rs.160/Trade, with RKG Rs.9/Lot and it comes around Rs.25/Trade
I usually do intraday in Options, where we have to wait for Rs.3 movement to breakeven the brokerage. (ex. buying Call 1 Lot @ Rs.60 and breakeven @ Rs.63 and above only I get profits) with RKG the breakeven is just 50ps (ex. buying Cal 1 lot @ Rs.60 and breakeven @ Rs.60.50)
So that I make more intraday with RKG even 1 Rupee profit trades done. (As I put stop loss with Re.1 profit) I do trade around 10 trades a day and I pay Sharekhan Rs.1600 and pays RKG Rs.250, just with 1 days I saved lots of brokerage.