Need path of all files which are being pulished for the first time and path of files which were modified before re-publishing the same content so that only modified files can be purged

I need these paths so that only new or the modified files can be purged instead of entire directory.
Is there a way to identify such files in Plone ???

What is a "module"?
There is no such concept in Plone.

By module I mean folder structure containing pdf, images, htm etc.

No idea what you are asking for. Rephrase your question please.

Based on how you ask the question: This sounds like (too) complicated programming.
What about just exporting all content as zexp and then remove all content when you reinstall your add-on and then import the zexp again.
You will probably need to have a 'folder at root' where you put your content, and make this 'navigation root' to be able to export everything in one go.

That said: 'Modified' is not easy to define ( is it setting a reference to another item or publishing something).

Something else that might be 'doable for you' is to make content rules that sends an email every time content is added or modified, then collect all the urls of the email and manually or by a script delete them
... or you could let the content rule 'add something to the items' so you are able to find them (maybe an index with 'is modified' and you could make a collection and delete them from there