Basketball
Basketball is played with two teams, with 5 players from each team on the court at one time. The maximum number of players on the bench differs by the league. In international play, a maximum of 7 players is allowed on the bench, resulting in a roster of 12 players. The NBA has 13-player rosters; college and high school teams have 15-player rosters. When a player wants to substitute for another player on the court, they let the score bench know. The referees will signal for the player waiting to come into the court. The player that was in the game comes off the court and the player that was  sitting on the bench goes inside the game. This is called a substitution. In regional matches, in some areas, a minimum of 3 players are required to be on the bench. In India, there might be leeway in the number depending on the category of the tournament you're playing in.