Cheapest Brokers in India ?

please tell me cheapest broker in india ?

Currently I am using Kotak Securities but it is very costly. I am paying 3p cuurently and looking for some cheap and good brokers who allows me to earn a bit instead of earning for them only.

I have heard some names in this forum like RKSV, Smart trade online and Achiivers etc?

Please help me to identify a good one?

I am looking for fixed brokerage system.

Thanks in advance !!:)