Irrlicht.Net is no longer developed or supported, Irrlicht.Net Cross Platform is a much more complete wrapper. Please ask your C# related questions on their forums first.
Dim mesh As Irrlicht.Scene.IAnimatedMesh = device.SceneManager.GetMesh(ModelPath)
If mesh Is Nothing Then
System.Windows.Forms.MessageBox.Show("Could not load mesh " + ModelPath, "Error Loading Mesh")
Return
End If
Dim meshType As Integer = mesh.MeshType.b3d