Unfortunately there is no standard for RJ to 9 pin adapters. On the 9 pin you will need to use pins 2, 3 and 5. If you are wiring both ends you can make a sort of universal adapter by wiring the ground (pin 5 on a 9 pin connector, pin 7 on a 25 pin connector) to the 2 outside wires on the RJ, pin 2 to the next 2 inner wires and pin 3 to the center 2 wires. This way it won't matter if your cable reverses the connection or not (of course, this requires that the cable itself use all 6 pins). You may have to swap the wiring of pins 2 and 3 on the multiport end depending on if it's using 9 or 25 pin connectors and whether it's wired as DTE or DCE.