Compare version numbers without using split function

Can you use the Version class?
https://docs.microsoft.com/en-us/dotnet/api/system.version

It has an IComparable interface. Be aware this won't work with a 5-part version string like you've shown (is that really your version string?). Assuming your inputs are strings, here's a working sample with the normal .NET 4-part version string:

static class Program
{
    static void Main()
    {
        string v1 = "1.23.56.1487";
        string v2 = "1.24.55.487";

        var version1 = new Version(v1);
        var version2 = new Version(v2);

        var result = version1.CompareTo(version2);
        if (result > 0)
            Console.WriteLine("version1 is greater");
        else if (result < 0)
            Console.WriteLine("version2 is greater");
        else
            Console.WriteLine("versions are equal");
        return;

    }
}

If you can live with the major.minor.build.revision scheme you could use the .Net Version class. Otherwise you'd have to implement some kind of parsing from left to right and continuing until you have a difference or return that two versions are equal.