[philso]

If your LED's are "rated for 12V" or "rated for 5V" they probably already have the proper current limiting resistors (or some other current limiting device) integrated into them. If you are connecting a 5V rated LED string to 12V, you will have to first find out how much current the the LED's draw, then calculate the series resistance value needed to drop the voltage across the LED from 12V to 5V.

There should be no need to connect the LED's to the VRM. The Voltage Regulator Module is for powering devices that are critical to the proper functioning of your robot and are sensitive to voltage fluctuations, like your radio. Your LED's are not a critical function of your robot (though some of the students on our team would debate me on this issue) and short voltage fluctuations will probably not make a noticeable difference in how they operate.