I have been trading / investing with Zerodha for around 5 years. I have traded only equities but they have commodities, FX etc too.Its the most popular broker in India.I never had a problem with them except those described belowTheir brokerage charges are one of the lowest in the country.Their margins not on the low side and they do not have any trading plans for reduction in brokerage (like Rs. 1000 for unlimited trading) and margins (like 4x leverage).Their prop platform, known as KITE (web, desktop, mobile) is really simple & fast. However it hangs/crashes in turbulent/news/volatile times. I have traded through many other brokers. Zerodha's platform is not as stable and sturdy as some of the others, but is very light on your PC whereas the others are very stable but microprocessor hungry.Zerodha's customer service is pretty prompt and to-the-point.Zerodha has several helpful tools for analysis / trading (algo/system etc.) too.