Folder Id null

Hi All,

        I m trying to delete old versions of rules using Delete Rules/Constants smart service in Contents Tools plugin. But i m not able to get the id for the rules folder which is a mandatory input.

So is there any way to get this folder ID or any other way/plugin to dynamically delete old versions of rules(As there are more than 200 rules(expression/Interfaces), doing it manually will be time consuming).

Request for your suggestions.

Thanks in Advance,

Pradeep