We can expect the market to go any side from here.
So let us be cautious with a strict stop loss.
Buy Bank Nifty Futures 30 AUG 18 when the 15 min candle closes above 27900
Sell Bank Nifty Futures 30 AUG 18 when the 15 min candle closes below 27760
Keep Stop loss and trail stop loss profit booking as per your calculations!