By default system has set 1 Currency - EUR.
From the Left menu, under Hotel Management - Currencies you define currencies, major currency, secondary currencies, and conversion rate. All prices you enter later (room, meals, ...) are in base currency. If you decide to adjust your conversion rate (for example, from your currency to EUR) then you will change this through this menu.
To Add new currency click on blue "Add New".
After adding new currency you will have list like this: