Elements 6 can only be updated to ACR 5.6 from Dec 2009. The update for ACR 5.6 is available, here:
However, if your camera is a model newer than Dec 2009, then it won’t work with ACR 5.6. Without knowing what camera you’re using and what operating system your computer has it’s hard to advise anything more specific.
Generally you either need to buy the current version of Elements (which is 13 until Sept/Oct) and be running an OS that is new enough to support PSE13, or use a DNG Converter with a version new enough to support the raw format of your camera and create DNGs from the camera’s raw files, then those DNGs will open in older ACR versions although there is some minimum ACR version that you’ll need to be able to work with DNGs. Hopefully ACR 5.6 would be new enough.
The DNG Converter is also available at the links, above.
Here is an Adobe reference that shows what minimum version of ACR or the DNGC is needed to work with raw files from every particular camera they support:
I'm using a Canon 550d & Snow Leopard 10.6.3.
Every time I click on the link you gave me a black screen loads that doesn't look like a fully loaded screen but Firefox says it's done loading. The screen says "manage accout" and "sign out".
I'm able to bring the links you sent me on my phone but not the computer....
The link got munged by my e-mail program and now that you replied I can't edit my message. Here they are, again:
If you look at the last link I supplied, that didn't get munged, the 550D needs ACR 5.7, which you cannot update your Elements 6 to use, so you'll have to go the DNG route, using DNG Converter 5.7 or newer to create your DNGs from the CR2 files. The DNG Converter converts a folder at a time, so you'll be selecting a source folder and won't see any images. That confuses some people.