Unable to redeem my Xbox 360 Gold games on my Xbox one.

It has always been like that not unless there will be an update regarding in redeeming Xbox 360 games with gold on the website. Xbox 360 marketplace has a different structure than on Xbox One Store. Xbox 360 games with gold on the website will need a payment
method. In Xbox 360 console, you won't need one. Currently, you can't redeem Xbox 360 games with gold using Xbox One console and still under progress about redeeming Xbox 360 games with gold on Xbox One console. Either get the games using an Xbox 360 console,
or get the games on the website with a payment method.

Sorry to hear it. If your account is considered a child account then the parent account will need to log in and make any changes to your purchasing authorization via their account.

Its my understanding that the 360 games are yours to keep. Xbox One games must have an active membership to play.

https://support.xbox.com/en-US/my-account/xbox-live-membership/games-with-gold-faq

“What happens to my Games with Gold games if I cancel my Xbox Live Gold subscription?

On Xbox One, you’ll no longer be able to access your Games with Gold titles if you cancel your subscription. However, if you decide to renew your subscription at any time, you’ll be able to access and play your previously
redeemed Games with Gold titles again.

On Xbox 360, any Games with Gold titles that you redeem as an Xbox Live Gold member are yours to keep, regardless of whether you continue your subscription.”

Alright but I still can’t redeem my fallout 3. The code is in a paper inside the disc case but it says that i need to change mynlanguage in order to redeem it. I live in the Philippines now but all of my language and location is marked at the united states
because thats where I bought my xbox one. And when i try to buy or redeem a free xbox 360 game from gold, when i click continue it always says “your account is unable to make this type of purchase on Xbox.com. Please complete this transaction from your Xbox.”

If they're the Games with Gold for the One, gold is required to continue playing them for free. The 360 games do not require gold to continue playing them.

From the FAQ:

What happens to my Games with Gold games if I cancel my Xbox Live Gold subscription?

On Xbox One, you’ll no longer be able to access your Games with Gold titles if you cancel your subscription. However, if you decide to renew your subscription at any time, you’ll be able to
access and play your previously redeemed Games with Gold titles again.

On Xbox 360, any Games with Gold titles that you redeem as an Xbox Live Gold member are yours to keep, regardless of whether you continue your subscription.