using System;

​

public class Program

{

​

    public static void Main()

    {

        string uriString = "6B%2FdHJaYVYZ9%2BkbVbNwB%2FmxPXwJhzmfIC8aUWOg%2F2mFCWzyrXaRHFsYLZSVedck3UW3FppuUG0jn2f4JMVUx9Q%3D%3D";

        string unescaped = Uri.UnescapeDataString(uriString);

        Console.WriteLine(unescaped);

    }

}