Hi prasad.ragal,
I don’t have knowledge of connecting PLC with Jetson Nano, I think you can check the PLC product spec to know which I/O can be used and u can check the OEM DG, pinmux and schematic to choose a spare I/O (ex. GPIO) for this in hardware, and set the trigger in software to generate output signal from this I/O(ex. GPIO) to PLC.
You can also refer to below topic to see if can gain some ideas: