multiple output data type for method in C#

Generally what I consider a better way is to return an object that contains all of the outputs you need. That may be a better solution for what you are looking for, cannot be sure.

private struct ReturnedObject
{
    public ReturnedObject(string variable1, string variable2)
    {
        Variable1 = variable1;
        Variable2 = variable2;
    }
    public string Variable1;
    public string Variable2;
}

private ReturnedObject SomeMethod ()
{
    return new ReturnedObject("first value", "second value");
}

There are exceptions, but C# is an object oriented language and should be using objects. I also prefer objects as arguments, otherwise some calls can become very long. The exeception to this would be where I am doing something like TryParse