(1) Subject to the provisions of section 19, when an application for registration of a trade mark has been accepted and either--
(a) the application has not been opposed and the time for notice of opposition has expired; or
(b) the application has been opposed and the opposition has been decided in favour of the applicant, the Registrar shall, unless the Central Government otherwise directs, register the said trade mark [within eighteen months of the filing of the application] and the trade mark when registered shall be registered as of the date of the making of the said application and that date shall, subject to the provisions of section 154, be deemed to be the date of registration.
(2) On the registration of a trade mark, the Registrar shall issue to the applicant a certificate in the prescribed form of the registration thereof, sealed with the seal of the Trade Marks Registry.
(3) Where registration of a trade mark is not completed within twelve months from the date of the application by reason of default on the part of the applicant, the Registrar may, after giving notice to the applicant in the prescribed manner, treat the application as abandoned unless it is completed within the time specified in that behalf in the notice.
(4) The Registrar may amend the register or a certificate of registration for the purpose of correcting a clerical error or an obvious mistake.