Typically to remove a region lock a person needs to use a local sim card from the same country the phone was bought in and make some calls to a local phone number. Around 10 minutes plus should do it.
If that's not possible then the Samsung Support people for the country the phone was released in maybe able to remove the region lock remotely.
This is typicallybif a person buys a phone and intends to then use it in another country i.e a grey import.
Phones purchased from Samsung are unlocked to all networks.
Phones purchased from a mobile phone network are typically locked to that network so wont accept another network sim card and thus need to be unlocked by the network that supplied the phone.
If a person just intends to roam in another country using their own networks sim card then all they need to do is check in with their networks customer services to ensure roaming is permitted on their account.