can I update my 2013 iMac to macSO Big Sur?

Cubano100 wrote:

Ohhh no! I need minimum 11.5 SO for a run a program. Any suggestions please?

Unfortunately, you'd need a new Mac: Mac - Apple.

Apple also sells refurbished Mac computers: Certified Refurbished Products - Apple.

Jack

No. Big Sur requires a 2014 or later iMac. Link-> macOS Big Sur is compatible with these computers - Apple Support