Once the re-indexing operation has been initiated for a vault, you can check the progress using the Re-Index File Properties Status dialog.
The Re-Index File Properties Status dialog indicates which vault is being re-indexed, what percent of the files have been re-indexed, as well as the total number of files that have been re-indexed and the number of files remaining. The re-indexing can also be stopped using the status dialog.
The Re-Index Status dialog summarizes the files that failed to be re-indexed.
Check the Property Re-Indexing Status