can i update my mac to version 12 if its an old mac air

• 2018 and later MacBook Airs can run macOS 13 Ventura ("the newest version"). Your tag line says that you are running macOS 10.13 High Sierra. There aren't any MacBook Airs that are old enough to run High Sierra and new enough to run Ventura.
• For Early 2015 and 2017 MBAs, Monterey is the end of the line.
• For Mid 2013 and Early 2014 MBAs, Big Sur is the end of the line.
• For Mid 2012 MBAs, Catalina is the end of the line.
• For Late 2010 and Mid 2011 MBAs, High Sierra is the end of the line.
• If your MacBook Air is earlier than that, it couldn't be on High Sierra now …

How to download and install macOS - Apple Support

To find your Mac's hardware model year, select About This Mac in the Apple () menu.

How old? That possibility depends on the exact year of the Mac