The climax of the story can be found toward the end of chapter six. What do you interpret as the “climax”? Why?

I usually define climax as that point in a piece of literature when the end becomes the end. Perhaps the end of 6 could be the climax because Winston begins to realize the depth of the Party's control of the people. His rebellion against such control ultimately leads to his being caught and discovering that physical pain is how they control rebels and that no physical joy is worth the hurt the pain can cause. This, of course, is how Winston is controlled at the end of the novel.