My car is from US and it uses miles when in my country we use kilometres and celsius scale.
How it can be swiched to our region?

 

Not sure that this is the case with our cars, but my dads vans instrument cluster went bad and when the dealership put in the new one it was in metric because they got it from canada, even the existing milage was translated from miles to kilometers. Anyways just a guess but from that experience I'd have to assume youd need a metric instrument cluster.