According to Newton's third law of motion, for every action, there is an equal and opposite reaction. If a player kicks a soccer ball with a force of 6 N, then the soccer ball exerts an equal force of 6 N back on the player's foot, but in the opposite direction.
Therefore, the soccer ball exerts a force of 6 N on the player's foot, and the direction of this force is opposite to the direction in which the player kicked the ball.