I have some additional notes. When reading your questions I think you might well need some basic understanding of electronics.
As the others already pointed out, the pins of an arduino are not fit to bear the current of a heavy load. But why is this a problem for you? This is because of basic laws of circuit theory. Have a look at Kirchhoff's Law for deeper insight. Important for you is the fact, that any one-port (i.e. a part with exactly two wires coming out) like the motors, magnets and regulators show the same current on each wire respectively. And if you compare current with pressurised air and conductors with pipes, a connection between two one-ports like your magnet and the regulator resembles a closed pipe with no means for the air to leak off sideways. Hence every liter of air which comes out of one part has to enter the next. With current it's the same. And a part with two connections (one-port) has the same properties. What goes in on the one side has to come out at the other side.
So, if your motor needs let's say 500 mA when driven with 6 V, the 500 mA will enter the arduino pin in your schematic damn sure. And 500 mA will heat up the tiny components of your arduino until they melt or crack and fail. The high current can be brought elsewhere by using parts with effectively more than two connections like transistors, but this is too much to explain right here.
The next thing are your voltage regulators. A one-port can only control voltage and currents between and at the connections of itself. So the voltage regulators in your circuit may well coerce a voltage of 6 or 5 V at its own wires but not elsewhere in this circuit. Hence the voltages on the motors and magnets may not be controlled like this.
Now go google some example circuits, basic information and come back with more information about
- power consumption of your motors (current or power)
- model number of the voltage regulator you intend to use
- an updated schematic
then it may be much easier to help.