Can you list which distros this applies to? How about Mint? (derived from Ubuntu I think.) What kind of processors does this work on? Intel Core i5 ? Or any chip that TrueCrypt will work with hardware AES acceleration I guess?
I have no idea what other distros run rngd by default. I'm sure it's available in all major distros, so it can always be installed. I believe the package is rng-tools.
If TrueCrypt reports that AES Acceleration is available, then the AES-NI requirement is fulfilled. As to whether your processor supports RDRAND, I believe all Ivy Bridge CPUs do. Quickest way to check your specific hardware would be to boot a recent Linux distro and type:
cat /proc/cpuinfo | grep -i rand
That was from memory, so there could be a mistake.... but if you receive output, you have RDDRAND, and if you don't... then sorry.