Filemaker does not repair corrupted files, so that is not an option. You will have to do this yourself or get a consultant to do it for you.
The best, cheapest alternative is to replace the files with undamaged backup copies and then import any additional data you need from the recovered copies. Sometimes this requires saving a clone of your backup and then importing all data from the recovered copies into the clone and then resetting any serial number fields that need to be updated.
If you don't have a backup copy, things get more difficult, but there are several options a knowledgeable developer can use to rebuild a corrupted file if a copy can at least be opened.