The particular question can have both a positive and a negative answer, and both would be correct. If we’re not talking about specific files, but everything within a partition that somehow disappeared, or a corrupted disk, then yes, it can. For that’s what TestDisk specializes in: recovering lost partitions and maybe fixing some minor problems with filesystems and a disk’s “structure”. However, it can’t recover individual files. For that, you can use Photorec, which accompanies TestDisk as a secondary solution. Or, even better, another alternative with a more user-friendly interface.