Yes, as all Macs except the Mac Pro from 2006 till 2008/2009 used 200-pin DDR2 RAM modules, thus you should be able to use RAM from a Mac from 2006-08/09 in a 2006 Mac mini. But the switch might be a pain in the arse, as the Mac mini is not that easily upgradeable.
Have you looked at iFixIt for guides and EveryMac for specs yet?