Sub es()
Dim m As Object, i As Long, z As Variant
Application.ScreenUpdating = False
Set m = CreateObject("Scripting.Dictionary")
For i = Cells(Rows.Count, 1).End(xlUp).Row To 3 Step -1
z = Cells(i, 1) & Cells(i, 2) & Cells(i, 3) & Cells(i, 4) & Cells(i, 5) & Cells(i, 6)
If Not m.Exists(z) Then m.Add z, z Else Rows(i).Delete
Next i
End Sub