To view your open orders on Arihant Plus, click on Trades in the bottom panel. 

You will enter the holdings screen by default, switch to "My orders" to check your order history.

Here you can see all your orders or choose to see only your open or closed orders. Click on "Open" in the navigation pane on top. 

You can also create a custom view of your order book by clicking on the filter button. You can understand more about creating your custom view here.