[Adam]

If you mean it bounced off the floor, it would have to go in prior to the horn. In this case, it would not count. The ball is live after a horn as long as the try might go in. Once the try will not go in, the game is over. In this case, the game is over as soon as the try hits the floor. If the bounce had been before the horn, the game would have been over as soon as the horn sounded. No basket unless it actually goes through before the horn sounded. And then, only two points.