ATM fees

You may not if that 6% is set by the government or some other agency. Generally the fees are set by and in this order --- owner of the ATM, networks fees for Visa and MC, and, finally, your bank. My guess is that the fees will be disclosed but if not. Then take out a hundred euro and see if you can determine the fee. It is possible that Croatia has a 6% on all debit card transactions. I apologize for this answer not being very useful.

You can avoid these fees in Croatia and any other country worldwide by having a debit card that allows for fee free use of ATMS worldwide. My Charles Schwab investor checking debit card refunds any fees charged by ATMS. For example, in January I used ATMs in South Africa twice. I was charged a $15 fee each time. I didn't worry because I knew it would be credited back. Sure enough, my February statement shows a $30 credit to my account to cover those ATM fees.

The Capital One 360 account has a similar policy, and I believe there are at least a few other options out there, including some credit unions. You can set up a Capital One 360 account online.

I have had a Schwab account with using debit card for years now. No transaction fees and ATM fees rebated back into account. Once I got this I never looked back. I have about 2-4 k in it per trip as I think I need before I go. With no fees for me I simply get what I need. Even if it is only $25. It’s a no brainer.

Croatia uses Euros. You can get them in a lot of countries other than Croatia.

I think you'll find the 6% is an exchange fee, not an ATM fee.