Muniza:
This depends on the regional version of AC you are using, as different regions have different libraries. In the USA version, the NCS Drawing Titles have an option to show "NOT TO SCALE" rather than the scale; but this text is not editable, so cannot show "NTS".
You should add a Signature to your Profile (click the Profile button near the top of this page) with your ArchiCAD version and operating system (see mine for an example) for more accurate help in this forum.
David