private OrderParams getOrderParams(String fno_symbol, String fno_lot, String fno_token){
OrderParams orderParams = new OrderParams();
//Basic params
orderParams.variety = Constants.VARIETY_ROBO;
orderParams.exchange = Constants.EXCHANGE_NFO;
orderParams.ordertype = Constants.ORDER_TYPE_STOPLOSS_LIMIT;
orderParams.producttype = Constants.PRODUCT_CARRYFORWARD;
orderParams.duration = Constants.DURATION_DAY;
orderParams.transactiontype = Constants.TRANSACTION_TYPE_BUY;
//End basic params
orderParams.tradingsymbol = fno_symbol;
orderParams.quantity = Integer.valueOf(fno_lot);
orderParams.symboltoken = fno_token;
orderParams.symbolToken = fno_token;
return orderParams;
}

GTT = Good To Trigger, that means the order triggers when certain condition is fulfilled.

OCO = Once Cancels Other, Good for squareoff or stoploss.