Apple has released a new version of iTunes that includes cross-device access to movies rented on iTunes. It will work as soon as the company releases new versions of tvOS and iOS, according to Macrumors.
tvOS, iOS & macOS
Hollywood is still imposes various and often strange limitations on movies available over the internet. Consumers on the other hand expect access whenever and whereever.
iTunes 12.6 finally abolishes this consumer-hostile limitation, meaning that you can "rent once, watch anywhere".
Up until now movie rentals on iTunes have typically been limited to the device on which you rented the movie, or a single device at a time. Similar limitations apply to other movie rental services.
However, before you can start enjoying all of this you need to update your iPhone/iPad to iOS 10.3 and your Apple TV4 to tvOS 10.2. These software updates are currently in beta and are expected to be released soon.