Computer Configuration > Administrative Templates > Google Chrome
Both
HKLM\Software\Policies\Google\Chrome
Setting the policy enforces a minimum Restricted mode on YouTube and prevents users from picking a less restricted mode. If you set it to: * Strict, Strict Restricted mode on YouTube is always active. * Moderate, the user may only pick Moderate Restricted mode and Strict Restricted mode on YouTube, but can't turn off Restricted mode. * Off or if no value is set, Restricted mode on YouTube isn't enforced by Chrome. External policies such as YouTube policies might still enforce Restricted mode.