2NT is 20-22, your 4s is transfer with at least slam invitational hand, 4NT from Nort is negative.
What do you bid and why?
I think, only pass, 5C and 6C are the possible solutions in a team tournament.
Would you agree with partner playing 5nt as transfer to 6C here?
If yes, now please bid 5nt instead of 6C.
Plus... it's free!