Rao dislikes Zim, but does not completely hate him. When Zim's life was in danger due to Tak trying to kill him, Rao teleported to his location to warn him about Tak.
Rao generally gets along with Dib. He somehow contacted him via radio when Dib traveled back in time.
Rao only knows Gaz by sight, and has not interacted with her as of yet.
Rao heard about Tak's failure to complete the Invader test when it happened 50 years ago. He also became allies with Tak for a short time before betraying her and getting incapacitated by her.
Rao tolerates GIR to an extent, and is somewhat patient with his randomness.