I am from India and my I9195 is not officially sold here. My schoolmate bought this device 5 months back from UK or Dubai.(Not sure where)
It had UK unbranded JellyBean firmware and then I immediately updated it to brazil jb and I never had network issues.
Even with kitkat firmwares I did not face network issues. Do you mean RegionLock results in unidentified networks in other regions? If so then my s4 mini is not locked.