Second hand Xbox 360 and we can not play 18 rated games due to family settings (from...

Can someone please clarify the parental control exception rule to me on a child's account?
If my child's account is set to 15, he cannot play Red Dead Redemption 2 as its rated 18 due to the parental control I have set. As a parent if I click ALWAYS does that automatically lift his account
 rating to 18 and allow him to play any 18 rated game or only ALWAYS for that one game?
Does that create a database of games that he is allowed to play by me the parent or just basically lifts the rating to 18? If it just lifts the overall content access to 18 rated I am unsure then
 why is that a permanent change that cannot be revoked.
"Grant an exception to your child’s content limits on Xbox One

Overview

If you want to grant your child permission to view content that’s rated higher than the child account settings for your family, you don’t need to change all of the settings to give access to a specific
content type, such as a game or a video.

Any adult in the family has the ability to grant exceptions to the content limits currently in the child account settings for your family. You have two options in granting exceptions:

• Always – This option grants a permanent exception that can’t be revoked.
• Just this once – This option is a one-off exception. It expires as soon as the child signs out of the console."

This is due to the family settings, you cannot play same games which are rated higher.

Hello its no way to change that since its from a previous owner. Unless you have contact with them to try to find out info. Sorry.

Your best bet would be to contact the previous owner and see if they can tell you the information so you can turn it off or change it.

If you mean the family code, follow the instructions from this page
https://support.xbox.com/en-US/xbox-360/security/forgotten-parental-controls-pass-code