Old iMac

What size is the display the size helps us determine which imac you own, an early 2009 or a late 2009.

• Early 2009 is 20" or 24" and can only go to 10.11.x
• Late 2009 are 21.5 or 27" and can go to 10.13.6. To update, use the Software Update feature in the Mac App Store or download it directly from How to get old versions of macOS

If you have a late 2009 iMac you can upgrade to High Sierra 10.13.6, which would upgrade Safari. Otherwise, no.