If you are missing only the sixth part, you must download it from the as the other parts to ensure they extract correctly. Common repositories for this specific board include:
Frequently provides direct links for T.VST59.A81 "all resolution" packs. Download VST59 A81 All Resolutions part06 rar
The file is part of a multi-volume archive containing firmware (bin files) for the T.VST59.A81 universal LED/LCD TV motherboard. If you are missing only the sixth part,