One company passed the interview, and the other is still waiting for the result. Can you tell this interviewed person to communicate with him in time?

You can start with the first one and wait for the second one. If you pass, it depends on whether you like the first one or the second one. If it is the second, just resign. If not, do it first! This is a sure-fire method. If you wait for the second company not to join the first company and the second company doesn't want you, then you are drawing water with a sieve.