During a doubles match a player on the opposite team was playing net and reached over to our side to return a ball. Can the racquet go over to the opposing team's side of the net to volley back a ball.

The racquet is allowed to cross the net as long as the ball is hit on their side of the court and the racquet does not touch any part of the net. In many cases, balls hit right over the net give the benefit of the doubt to the attacking player. However, if it is clearly on your own side of the court, it would be considered a fault and you would win the point.