as many as needed, games are usually decided in 1 or 2, but there is no limit
If a game is that miraculous then Yes it can go 5 overtimes
As far as college and NBA is concerned, there is no limit as to the number of overtimes that can be played before determining a winner of the game.
Usually an overtime lasts 5 minutes but it depends how many overtimes they go in to.
As many as there can be, As long as they keep tieing they can be as many as possible.
Yes, in 1989, in the Celtics v. Hawks game.
The Indiana Olympians defeated the Rochester Royals 75-73 in six overtimes--the longest game in NBA history
Six overtimes in a game between Indianapolis Olympians and the Rochester Royals on January 6, 1951. Indianapolis won 75-73 in this 4 hour game.