6NT makes if ♣s break 2-2, however if they break 3-1 and the ♣Q does not drop, even 3NT will be in danger since South is nearly entryless. If ♣s are trumps, again, if the ♣Q drops, there is a slam. If it does not drop, the slam makes when a finesse in either ♠ or ♦ is successful since the extra winner can cover a loser in ♥s. However, if the finesse fails, the opponents are able to draw the ♥ loser immediately. 5♣ is cold in this case.
What contract will you bid and how will you bid it? If North deals, 1♠ is opened; if South deals, 4♣ is opened.