A .rar file with this name might include components similar to those found in developer tools like Newtonsoft.Json.Portable :
You will need a utility like 7-Zip Portable or WinRAR to extract the .rar file. Archivo de Descarga JSON-Portable.rar
Since it is "Portable," you do not need to run an installer. Simply double-click the file to start working with your JSON data. Security Warning Archivo de Descarga JSON-Portable.rar
Essential code libraries that allow the program to parse and validate JSON structures. How to Use the Downloaded File Archivo de Descarga JSON-Portable.rar
Based on common technical use cases for such files, here is content explaining what this package likely contains and how to use it: What is "JSON-Portable.rar"?