Hi socc3rpr0,
Please keep in mind that TestComplete is a GUI testing tool, it's not really suitable for .NET API unit testing. Consider using a unit testing tool like NUnit, MSTest, xUnit.net, etc.
That said, your example is almost correct. You only need to specify the appropriate type - IP or Devices - for objType:
var objType = dotNET.System.Type.GetType("Namespace.Whatever.IP");
var objType = dotNET.System.Type.GetType("Namespace.Whatever.Devices");
The assembly containing the IP and Devices classes needs to be in the CLR Bridge list.
Once you have created the list you can add list items as follows:
var ip1 = dotNET.name_space.IP.zctor(parameters);
var ip2 = dotNET.name_space.IP.zctor(parameters);
list.Add(ip1);
list.Add(ip2);