I phone 6

If you forgot the passcode [including a restrictions passcode] for your iPhone, iPad, or iPod touch, or your device is disabled - http://support.apple.com/HT204306 - You can restore from a backup but that backup has to date from before you set the restrictions password.

If you can't update or restore your iPhone, iPad, or iPod touch - https://support.apple.com/HT201263

Hi!

It is not possible to create a new one, without restoring the phone and setting it up as new. Read more here: Use Restrictions to prevent purchasing on your ... - Apple Support

Petter