the k6c16 will use a straight-thru serial cable.
In RSLinx use the RS232 DF1 devices driver.
You should be able to 'auto-config' the driver and see the PV.
In PB32, select download.
Make sure transfer type is set to rslinx network
on left side, select the DF1 driver and on the right select the PV
click OK
also be aware that the k6c16 has two serial ports, one for comms and the other for printing.