Why can’t I play Red Dead Redemption the 360 version on my Xbox one?

Keeps telling me that there’s a problem with my credentials that I’m using to sign in with. Code 8007274C

I cleared my 360 storage from console so hopefully this helps…

There's no native Xbox One version of Red Dead Redemption. The one you see on the xbox store, is the 360 version made compatible on the system. The base game is on sale on xbox 360, but the dlcs are not on sale. Its best to get Red Dead Redemption Game
of The Year edition as it would have all dlcs included.

I suggest you read thru
support.xbox.com/.../compatibility-with-xbox-360-faq to get an idea how things work.

So yes, the 360 game will show up on xbox one ready to install, which means you'll be getting the xbox one version of the 360 game running in an emulator.

Firstly, the retail full version of Red Dead Redemption 2 on disc already includes Red Dead Online so unless you have transitioned to a digital only console, you wouldn't need to purchase it again.
Secondly, which digital version did you purchase? There is the full game Red Dead Redemption 2. There is also Red Dead Online, which is obviously the online part. And then there is Red Dead Redemption 2: Story Mode, which is just a DLC for Red Dead Online (owning Red Dead Online is required) which allows you to play the single player campaign.
Please check your purchase history to see which one you have purchased.

Red Dead Redemption 2 is not available for the 360. You would have to play it on the One.