What is the latest firmware can be installed in MacBook pro 2012 model?

If your 2012 MacBook Pro requires any firmware update, the latest operating system that can support it will install that firmware. Nothing for you to do. That can be Catalina at this point in time.

AswanthP wrote:

What is the latest firmware can be installed in MacBook pro 2012 model?

If your EFI firmware version seems out of date, download the last Combo updater and/or subsequent Security Updates for the version of macOS which you are running, from Apple Support.

 EFI firmware updaters are now only distributed as part of macOS updates and upgrades,

Apple no longer provides them separately.

do you mean firmware or macOS operating system ?