Oops, sorry, instead of Clear, you should put ClearContents, could have seen it from your question.
Sub DeleteRows()
Dim lr, i As Long
Dim ws As Worksheet
Set ws = ThisWorkbook.Worksheets("TaskTracker")
lr = ws.Range("A65536").End(xlUp).Row
For i = lr - 1 To 12 Step -1
ws.Cells(i, 1).EntireRow.Delete
Next i
For i = 11 To 7 Step -1
ws.Cells(i, 1).EntireRow.ClearContents
Next i
End Sub