When using OCO orders in GTT, you'll need to set both Stop Loss and trigger price and Target price for the stock. If the LTP hits the Stop Loss trigger price first, then the  SL order will be sent to the exchange, and the Target order will be automatically cancelled. Conversely, if the stock hits its target first, the Target order will be executed, and the Stop Loss order will be cancelled.

​For more details, refer to the CubePlus User Guide by Tradejini​

Make sure to carefully check the order box and set your target and stop loss accordingly.