Haris,
What kind of data are you working with here? WTParts or CAD Documents? If you're working with CAD Docs you can upload the new CAD data from the workspace without checking in. After the data has been uploaded you can then select File > New > Revision and set the revision for the new cad data. In order to specify specific revisions make sure that the Revise > Override on Revise preference has been set to Yes in Preference Management.