You may consider nifty 50 stocks. Liquidity is good enough over here.
If you want to reduce risk sell nifty index puts. You can even sell weekly puts. If it comes ITM either convert them to futures or buy niftybees equivalent to 1 lot. And then you can start selling higher level calls.
Considering the margin involved, you can make 3 to 5 percent of margin blocked per month by doing this. The next question is what are you gonna do with the remaining balance until your position comes ITM.
You need around 9lakhs for 1 lot of nifty. You have to keep these funds ready incase you have to buy a whole lot. You may consider keeping them in debt funds. If you do this your annual return on your total investment comes around 15 to 18 percent.
Now if your capital is 15lakhs, is that enough for all the efforts that you have put in. So I feel minimum capital should be around 50lakhs to actually make decent returns.