This is a compression format. To use the update, you would need to extract the .nsp file from the .rar archive using software like WinRAR or 7-Zip. Important Considerations: Safety and Legality
Many NSP updates are encrypted or signed to prevent unauthorised execution. Tools that strip, modify, or forge tickets and signatures are often classified as “circumvention devices.” Under statutes such as the U.S. Digital Millennium Copyright Act (DMCA) or analogous EU directives, the distribution of such tools is prohibited.