If I have to introduce someone in a meeting what should I say?
I would like to introduce X who has joined us from Y company.
I like to introduce X who is joining us from Y company.
"I would like to introduce" is the polite way of phrasing "I introduce", which is what you want to do here.
"I like to introduce" says that you personally enjoy the act of introducing, which is not what you are after at all.
Quite independently of that, you should pick whether you say "has joined", "is joining", "joins", "joined", "will join" or whatever according to the normal rules of tenses. There's nothing unusual about the subordinate clause here; "has joined" tells us that X has already completed his move, "is joining" tells us that it is still being sorted out as we speak, and so on.
You could use any of the following:
Typically you would use "is joining" or "joins" if the hiring has been accomplished recently or will be completed in the immediate future.
Its all a matter of tense
Would be the introduction on his first day as he has already joined the company.
Would be for introducing him after the interview and his acceptance but before he starts working for you.
That said, both would be understood perfectly well and I doubt anyone would be pedantic enough to call you on it.