law: 21. Provisions as to exhibitions.-
  The exhibition of a design, or of any article to which a design is applied, at an industrial or other exhibition to which the provisions of this section have been extended by the Central Government by notification in the Official Gazette, or the publication of a description of the design, during or after the period of the holding of the exhibition, or the exhibition of the design or the article or the publication of a description of the design by any person elsewhere during or after the period of the holding of the exhibition, without the privity or consent of the proprietor, shall not prevent the design from being registered or invalidate the registration thereof:
  Provided that-
  (a) the exhibitor exhibiting the design or article, or publishing a description of the design, gives to the Controller previous notice in the prescribed form; and
  (b) the application for registration is made within six months from the date of first exhibiting the design or article or publishing a description of the design.