Just an FYI, Debian is not an officially supported Host OS for VMware Workstation and whatever version you try to install may require 3rd party patches and or workarounds for any issue that might arise. Also VMware Workstation 6.x is not available for purchase and it reached end of general support on 10/01/2011. So unless you already own a copy then you'll not be able to get a license key from VMware.
As to installing it, I'd search Google for "install vmware workstation on debian" and go from there.