Aquí tienes la solución:
Sub analisis()
fila = 1
Range("c1").Select
Do While ActiveCell.Value <> ""
If Application.WorksheetFunction.CountIf(Columns(3), ActiveCell) = 1 And Application.WorksheetFunction.CountIf(Columns(6), ActiveCell) = 0 Then
Cells(fila, 21).Value = ActiveCell.Value
fila = fila + 1
End If
ActiveCell.Offset(1, 0).Select
Loop
Range("f1").Select
Do While ActiveCell.Value <> ""
If Application.WorksheetFunction.CountIf(Columns(6), ActiveCell) = 1 And Application.WorksheetFunction.CountIf(Columns(3), ActiveCell) = 0 Then
Cells(fila, 21).Value = ActiveCell.Value
fila = fila + 1
End If
ActiveCell.Offset(1, 0).Select
Loop
End Sub