Text: During Microsoft's E3 2015 press conference on June 15, 2015, Microsoft announced plans to introduce Xbox 360 backward compatibility on the Xbox One at no additional cost. Supported Xbox 360 games will run within an emulator and have access to certain Xbox One features, such as recording and broadcasting gameplay. Games do not run directly from discs. A ported form of the game is downloaded automatically when a supported game is inserted, while digitally-purchased games will automatically appear for download in the user's library once available. As with Xbox One titles, if the game is installed using physical media, the disc is still required for validation purposes.

Question: will an xbox one game work on an xbox 360?
yes