How to describe Active Cell in a " Do - Loop" macro

Maybe:

Sub Dorocica()
Dim i As Long
Range("A2").Select
Do Until ActiveCell.Row > Range("A" & Rows.count).End(3)(1).Row
    ActiveCell.offset(66).Resize(4).Interior.ColorIndex = 6
    ActiveCell.offset(66).Select
Loop
For i = Range("A" & Rows.count).End(3)(1).Row To 2 Step -1
    If Range("A" & i).Interior.ColorIndex = 6 Then
        Rows(i).Delete
    End If
Next i
End Sub

Test on a copy first to see if it does what you want.