Welcome to the forum
Take a minute to read the FAQ t the link in my sig
Try this bit of code and take a look at the attachment. It isn't the most elegant, but should be agood starting place for you
Option Explicit
Sub AddNumber6()
Dim r As Long, rBottom As Long
Application.ScreenUpdating = False
With ActiveSheet
rBottom = .Cells(.Rows.Count, 2).End(xlUp).Row
'best to go bottoms up
For r = rBottom To 2 Step -1
If .Rows(r).Cells(2).Value = 5 Then
.Rows(r + 1).Insert Shift:=xlDown, CopyOrigin:=xlFormatFromLeftOrAbove
.Rows(r + 1).Cells(2).Value = 6
.Rows(r + 1).Cells(3).Value = "New City"
End If
Next r
End With
Application.ScreenUpdating = True
End Sub