Files with nak file extension might be found as very old audio files. Probably no longer supported.
NAK file extension - Audio file
What is nak file? How to open nak files?
File type specification:
The nak file extension seems to have been in the past used for some sort of audio format.
Probably long forgotten and no longer used file format without support from developer.
This nak file type entry was marked as obsolete and no longer supported file format.
This type of file is no longer actively used and is most likely obsolete. This is typically the case for system files in old operating systems, file types from long discontinued software, or previous versions of certain file types (like documents, projects etc.) that were replaced in higher versions of their original programs.