The document management systems supported by migration-center have different policies regarding file names: Some systems, like OpenText Documentum, allow files with identical names in the same folder. Other systems, like file system or Microsoft SharePoint, require unique file names in a folder.
If you migrate documents into a system that requires unique file names in a folder, it is best practice in migration-center to create unique file names by adding some unique value to the file names. For example, if the source system is OpenText Documentum, you could use the unique ID attribute of the source documents ("r_object_id" in Documentum) to create a unique file name. To do so, setup a transformation rule for the target file name rule "content_target_file_path" that concatenates the source file name (from source attribute "object_name") and the source unique ID (from source attribute "r_object_id"). See the screenshot below for an example:
Of course, it depends on the source system, which attributes can be used to generate a unique file name.