This is what i want to do:

And I tried anwsers in this thread too ;-How do I delete a cell from Excel which contains less than 3 characters? I have only one column in sheet
But I can't get it to work.
I tried some codes like these after searching for a few hours but none of them worked or maybe I am not doing it correctly:
Code 1:
With ActiveSheet
lastrow = .Cells(.Rows.Count, "N").End(xlUp).Row
For i = lastrow To 2 Step -1
If Len(.Cells(i, "N").Value) < 6 Then
.Rows(i).Delete
End If
Next i
Code 2:
Sub M_snb()
[N1:N100] = [if(len(N1:N100)<6,"",N1:N100))]
Columns(14).SpecialCells(4).EntireRow.Delete
End Sub