Purchase of Backwards compatible Games

Are you trying to buy One games or backwards compatible games? The Microsoft account balance cannot be used to purchase backwards compatible content on the One.

The One store/website have never been updated to work with the currency system for backwards compatible content. The only way to purchase backwards compatible games with the funds on your account is through a 360 console.

Oblivion is backwards compatible so it will work on the One X. You can view a list of backwards compatible games at https://www.xbox.com/xbox-one/backward-compatibility/available-games

If the Xbox 360 games you purchased are backwards compatible on Xbox One you will be able to play them.

https://www.xbox.com/en-US/xbox-one/backward-compatibility

The link above will provide you with a list of games that are backwards compatible.

Depending on the game it may not be compatible on Xbox One if the game is not backwards compatible. The game may only playable on an Xbox 360.

There is a list of games that are backwards compatible and I believe the game will say if it is or not before purchasing it.

Hope this helps.

Currently, no. Even with the current phase of backwards compatibility, those games are not backwards compatible yet. So you would need to purchase the Xbox One version if you want to play them. As far as in the future, it depends on whether or not the games
are made backwards compatible.