Roku themselves does not restrict channel/app availability. The channel providers can restrict access to their channel in two ways. One would be the country that your Roku user account was created in. The other is determining your current location by your IP address, and not permitting access in unsupported locations.
There are two ways to add channels to a Roku device. One is on the device itself. On the main Roku screen there are a number of options available, one being labeled "Streaming Store". At least that's the name it has in the US. Any channels that are available for your location and account will be listed there. The other way is using the Roku website channelstore.roku.com. There you can find channels that are available for your location (or at least the location selected at the bottom of the page) and can be linked to your account. Once it's on your account it will self-install on your device at the next update, or you can force an update from the device menu. Just be aware that the web site doesn't know what device you're installing the channel to, and if the channel isn't supported by your device it will not install. Usually that only happens with an older device that won't work with newer channels.
Dan
Roku Community Streaming Expert
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