Buy Nifty Put @ strike 8700 and Call @ strike 8900. This will open a straddle position. With the US fed decision coming in today we can expect large moves in either direction if Fed does anything that the market is not expecting. Risk is low and potential profits are unlimited. Position size your options according to your trading capital. Make sure to exit your positions tomorrow morning at market price when market opens. If you were to benefit it would have been done by tomorrow morning through a large opening market gap to the up or down.