How to get all work items which contains attachment in RTC 3.0.1
One answer
RTC 3.0.1 is so far in the no longer supported area, that I don't even have it anywhere in access.
The question is pretty open and does not provide any business/use case, so here a short answer.
In general you could create a work item query and select a condition Attachment exists. That would give you all work items of a project area with an attachment.
In addition educate yourself in in what attributes an attachment has (in creating the work item query). E.g. it has only a name and no path. A path would not make any sense either. the attachments in work items are stored in a blob in the database. You only have access to that through the UI and APIs.