The Trade Marks Act,1999
33. Effect of acquiescence.—
(1) Where the proprietor of an earlier trade mark has acquiesced for a continuous period of five years in the use of a registered trade mark, being aware of that use, he shall no longer be entitled on the basis of that earlier trade mark—
(a) to apply for a declaration that the registration of the later trade mark is invalid, or
(b) to oppose the use of the later trade mark in relation to the goods or services in relation to which it has been so used,unless the registration of the later trade mark was not applied in good faith.
(2) Where sub-section (1) applies, the proprietor of the later trade mark is not entitled to oppose the use of the earlier trade mark, or as the case may be, the exploitation of the earlier right, notwithstanding that the earlier trade mark may no longer be invoked against his later trade mark.
The proprietor of the earlier trade mark or other earlier right cannot contest the validity of registration of a subsequent trade mark, if he has acquiesced in the use of the subsequent trade mark for a continuous period of five years, unless he can prove that the registration of the subsequent trade mark was not obtained in good faith. The proprietor of the later mark also is not entitled to oppose the use of the earlier trade mark.