Zerodha is one of the best discount broker available in India at present moment. Zerodha charges 20/ order which is very low as compare to Sharekhan, Angel broking, etc. If you compare Zerodha vs Sharekhan you will find lot of difference in overall charges.
Zerodha provide call and trade facility and online platform also. Zerodha has 2 online platform Kite and phi software which is also very helpful for charts and technical tools.
The only disadvantage of Zerodha is only that they dont have more branches like Sharekhan, Angel broking do have.
