Game not showing up in ready to install

It should show up pretty much immediately

If you have two email addresses and potentially two accounts you may have to request for a refund if you purchased the gams under the incorrect email/account.

Verify the account by logging in to Microsoft.com with the account and check you purchase history.

Good Luck

Have you already tried refreshing the My Games & Apps app on your console?

You can do this by opening your guide on the console by pressing the controller power jewel once. Highlighting the My Games & Apps tab. Then press the menu/start button on your controller and selecting refresh.

If after you refresh the My Games & Apps app. You're still unable to find the games in the Ready to install list. Go into the Store on your console and find the game you've purchased. If your account owns the game. When you look in the games store page.
You'll see the option to install instead of purchase.

Hey- my xbox came with rainbow 6 siege but it was a code, and when I uninstalled it (needed space) it just disappeared and in the store it says I need to purchase it- how can I get it back without buying the game pack?

search for the game in the store , ive installed from there when this happend to me