We can manage to get in the range of 200 - 800 points in NIFTY Futures on monthly basis, but remember, the higher side is purely depends on the performance of the execution, success rate of the strategy & market conditions etc. Some times, even market can go in negative (max draw down is around - 170 points in last three years), so nothing is concrete in the trading business. What I can say that, we can get an average monthly return of 10 - 15% on your investment, which is more or less double on yearly basis.
You are doing brilliantly than him provided you are trading with such hefty amounts. A prospective billionaire secret.. Good luck.