Hi Daniel,
OEM licenses are sold to PC manufacturers or Windows installers who sells the assembled PC.
The end user cannot buy OEM separately from computer from its own needs - there is system builder license agreement on the back of the pack and its obliges builder to sell a PC after Windows installation.
If one buy OEM separately from computer it is either in pack (see picture) or sold illegally.
There is no sense to buy OEM packs in another country so your question is senseless too, unfortunately..
But no doubt there are very small limitations to export PCs with Windows to other regions. see
https://www.microsoft.com/en-us/exporting/overv....