Sorry Pinky, but I think a ruck can become a maul.Taff, a maul can become a ruck if the ball is on the floor as that ends the maul and if there are players closing round the ball on the floor that is a ruck. I don't think it can happen the other way as picking the ball up legally does not end the ruck, so it is still a ruck.
If a jackler manages to lift the ball off the ground legally and all the other criteria for a maul are met (ball carrier on his feet and 2 opposing players bound on) surely it wouldn't make sense to treat it as a ruck when we are looking at a clear maul.
I haven't got them to hand, but I'm pretty sure there has been a clarification on this.