J'ai trouvé la solution c'était tout bête
Sub incre2()
Dim FirstRow, LastRow, FirstColumn, LastColumn, TabWide, Tabheight As Integer
FirstRow = 4
FirstColumn = 11
LastColumn = FirstColumn
Dim rowout As Integer
rowout = 4
Dim C As Integer
C = FirstColumn
'For N-1
Tabheight = Sheets(1).Cells(FirstRow, FirstColumn).End(xlDown).Row
TabWide = Sheets(1).Cells(FirstRow, FirstColumn).CurrentRegion.Columns.Count
Dim SelectedRows As Integer
For SelectedRows = FirstRow To Tabheight
Sheets(1).Cells(rowout, 6).Value = Sheets(1).Cells(SelectedRows, C).Value
X = Sheets(1).Cells(SelectedRows, 12).Value
If X > 1 Then Sheets(1).Cells(rowout, 6).Resize(1).AutoFill Destination:=Sheets(1).Cells(rowout, 6).Resize(X), Type:=xlFillDefault
Sheets(1).Cells(rowout, 6).Resize(X).FillDown
If X = 1 Then Sheets(1).Cells(rowout, 6).Value = Sheets(1).Cells(SelectedRows, C).Value
rowout = rowout + X
Next SelectedRows