Unlock an iPhone 5c with Brazilian SIM card?

My bro gave me an iPhone 5c that he found 2 years ago, which he couldn't unlock. It was some brazilian tourist I assume since the last country in the settings shows Brazil and the SIM card says VIVO chip, which I have found is Brazilian. I have tried changing the DNS server on the phone but nothing works. I also tried calling 112. Can anyone help?

No. It's a stolen phone. "Finders keepers has no legal basis" in any civilised country but "theft by finder" is a well-established legal principle.

Changing the DNS would not unlock an iPhone… Or any phone for that matter. In any case Activation Lock would prevent anything else from happening anyway.