There are 52 names in your file not 50 names. It seems you forgot to put a sequence numbers for two students
Try the following code
Sub Test()
Dim lr As Long, r As Long, m As Long
Application.ScreenUpdating = False
With Sheet1
lr = .Cells(Rows.Count, "B").End(xlUp).Row
m = 3
For r = 3 To lr
.Cells(m, 6).Value = .Cells(r, 2).Value
.Cells(m, 7).Value = .Cells(r, 3).Value
m = m + 3
Next r
End With
Application.ScreenUpdating = True
End Sub