When do you draw the extra card from Bay of Ice before or after the when revealed effects?

You draw as a passive after you've revealed plots.

While technically "When revealed" effects are also passives, they are specifically separated in the FAQ and occur *before* other passives. You would resolve all "When Revealed" effects prior to resolving any other passives; e.g. Bay of Ice, but before resolving any responses triggered by revealing plots, any of the plots effects, or drawing from bay of ice.

So if my opponent plays the plot ''Negotiations at the Great Sept'' and i don't have a card to shuffle even though i have a Bay of Ice in play and won the initiative,i can't take the 5 cards right?

Correct.

Thank you very much!!!!!!