Are you asking:
1) Can you run Linux binaries on a 64bit FreeBSD system?
or
2) Can you run 64 bit Linux binaries?
The answers:
1) Yes
2) Perhaps the linuxolator supports it, I don't think so, but I'm not 100% sure.
It certainly won't run "out of the box". This would require two versions of all the libraries (32 and 64 bit), which are not installed by the linux-* ports.
For most applications, there is no real advantage other than the ability to use >4GB memory.