The distribution and downloading of .nsp files (and associated .rar archives) for games one does not legally own constitutes software piracy, which is illegal in most jurisdictions and violates the Digital Millennium Copyright Act (DMCA) and similar international laws.
Given this information, the filename seems to suggest that it is an archive (RAR file) containing an update for the game "Inscryption" on the Nintendo Switch, presumably in NSP format. Inscryption -NSP--Update 1.41.2-.rar