Can i get my older imac refurbished?

Providing the screen size and sub-model as dialabrain has requested is an excellent place to start because iMacs recently celebrated their 21st birthday as a product line and there are hundreds of variants!

Also what Mac OS version is it running?

What is the reason for seeking refurbishment? If your computer is not performing well, tell us the symptoms and perhaps we can help you improve its performance without your having to take the computer anywhere. Very often, slowness or stability issues are due to unneeded software, something that can be easily corrected without seeking professional help.

Not that I know of. You didn't mention how old btw.