Sub CheckBox1()

Dim cb As CheckBox

For Each cb In ActiveSheet.CheckBoxes
    If cb.Name <> ActiveSheet.CheckBoxes("Check Box 1").Name Then
        cb.Value = ActiveSheet.CheckBoxes("Check Box 2").Value = True
End If

Next

End Sub
Sub CheckBox2()

Dim cb As CheckBox

For Each cb In ActiveSheet.CheckBoxes
    If cb.Name <> ActiveSheet.CheckBoxes("Check Box 2").Name Then
        cb.Value = ActiveSheet.CheckBoxes("Check Box 3").Value = True
End If

Next

End Sub
Sub CheckBox3()

Dim cb As CheckBox

For Each cb In ActiveSheet.CheckBoxes
    If cb.Name <> ActiveSheet.CheckBoxes("Check Box 3").Name Then
        cb.Value = ActiveSheet.CheckBoxes("Check Box 1").Value = True
End If

Next

End Sub
Sub CheckBox4()

Dim cb As CheckBox

For Each cb In ActiveSheet.CheckBoxes
    If cb.Name <> ActiveSheet.CheckBoxes("Check Box 4").Name Then
        cb.Value = ActiveSheet.CheckBoxes("Check Box 5").Value = True
End If

Next

End Sub
Sub CheckBox5()

Dim cb As CheckBox

For Each cb In ActiveSheet.CheckBoxes
    If cb.Name <> ActiveSheet.CheckBoxes("Check Box 5").Name Then
        cb.Value = ActiveSheet.CheckBoxes("Check Box 6").Value = True
End If

Next

End Sub
Sub CheckBox6()

Dim cb As CheckBox

For Each cb In ActiveSheet.CheckBoxes
    If cb.Name <> ActiveSheet.CheckBoxes("Check Box 6").Name Then
        cb.Value = ActiveSheet.CheckBoxes("Check Box 4").Value = True
End If

Next

End Sub