If there is an app with the content you want that has free streaming, then you should be able to view it. If it is an app with content that requires a subscription, then you will need to subscribe to view it, regardless of the streaming device you have.
The best thing to do is look for the channels you want in the Roku store and see if they are free or require a subscription to view. This is assuming that the apps do not have any local restrictions.
