Validity is used to specify the system that order's validity should be day or IOC(immediate or cancel). If validity is DAY, your order stays in the system till it finds a counter party for the whole day. If validity is IOC, your order will be either executed immediately if a counter-party is available or it will be canceled.
scrip name is ICICIBANK and you need to pass validity also.
You can check out example for placing order here
If validity is DAY, your order stays in the system till it finds a counter party for the whole day.
If validity is IOC, your order will be either executed immediately if a counter-party is available or it will be canceled.