Depending on what Google service you use to make a purchase, the currency that you're billed in may not be the currency of your home country.
How currency conversions work
If possible, Google will charge you in the currency of your home country. Google gets this information from the home address that you added.
If that isn't possible, you'll be charged in a different currency. For those outside of the United States, this usually means being charged in US dollars.
Note: You'll always see the currency that you'll be charged in before you complete the transaction.
Update your billing country
If you've moved to a new area, you can update your home address so that you'll be charged in your home currency.