Princesly,  The R610 does support 2012. Have you tried booting directly to the 2012 media? It sounds like you were trying to use a Dell OS install disk.  What happens when you boot to the media? Also, have you attempted the install using the Lifecycle Controller (F10 at Dell screen)? 
Hello-- Does anyone know how to update R610 so that I can install 2012 from the BIOS? I tried as "other" in F10 and it failed with driver errors. I tried updating the firmware with the management ISO and the same thing occurred.  Is there a method i am missing?  Thanks, Prince
Windows Server 2012 on Dell PowerEdge R610