I have a issue. when i am doing revision manger i can add only assy 2d draft document but how to add child parts 2d drawings. Attached image for reference in that no 2d drawings attached for part files
Select the files you want to find drafts for then Tools > Assistants > Where Used.
On the form that appears you can select the locations to search and whether to include/exclude sub-folders.
The Process Options button will let you restrict the file types to search for.
The new design manager makes that process much much easier. You can now start with a draft, get the assembly and parts, then also add any other draft files associated with the assembly or any parts.
I never could get that working with the old revision manager where you copied a collection of related files including multiple drafts.