I have a game digitally on xbox 360 that is backwards compatible with xbox one, but it...

Keep in mind that many of the Xbox 360 games are not yet backward compatible for xb one, you should check if the game you are trying to play is backward compatible with Xbox One, if you have them in digital format go to your games library on Xbox One and
there You will find the games that are backwards compatible ready to download, or you can also search the complete list of backwards compatible games from xb 360 to xb one current on the web.

If you wish to play the games that you own on the Xbox 360 on the Xbox One, then those games (digital/physical) has to be supported for backward compatibility on the Xbox One. For digital games, that are part of the backward compatible list, show up in the
"Ready to install" section of your Xbox One. The criteria for these titles to populate the "Ready to install" section is that you have to be signed in with the same account that you initially used to purchased those games on your Xbox 360.

http://www.xbox.com/en-US/xbox-one/backward-compatibility#faqSection

http://www.xbox.com/en-US/xbox-one/backward-compatibility/available-games

You can play some Xbox 360 games on Xbox One through backwards compatibility. A full list of those games is here:
www.xbox.com/.../backward-compatibility

However, games for which there are both an Xbox One and Xbox 360 version are unlikely to ever be made backwards compatible, so if you wish to play that game on Xbox One you would need to purchase, either digitally or on disc, the Xbox One version of the
game.

I hope this helps. Let us know if you have further questions.

If a game is not compatible with Xbox One, whether it's a digital or disc version, it cannot be played on the console. However, some Xbox 360 games are backward compatible with Xbox One, and you can check the list of backward compatible games on the Xbox website. If the game you purchased is on the list, you can download and play the digital version on your Xbox One.

Xbox One will not be backwards compatible with Xbox 360 games, digital or discs, so I would suggest you hang on to your Xbox 360.