Yes.
There are 3 kinds of copies of the game.
North America, Europe, and Asia, because there are 3 types of Nintendo 3DS with region locks. They're coded to make sure they don't work in foreign DS's. Which is why Japanese games don't work on European or North America 3DS's.
NA:
Canada
Mexico
United States
etc.
Europe/PAL:
United Kingdom
France
Italy
Australia, etc.
Asia:
Japan
Korea
Singapore etc.
So an American ditto can breed with a British pikachu to produce a shiny pikachu because they are PAL and NA versions of the game.
However, a Canadian Pikachu and U.S. Ditto won't activate the masuda method.
It's not based on what location you choose on your 3DS either, it's dedicated to your hardware what version you have.
