Notwithstanding anything contained in this Act or any law for the time being in force, the Central Government or, as the case may be, the Director-General with the prior permission of the Central Government, if is of opinion that it is necessary or expedient in the public interest so to do, may, by order in writing and subject to such conditions and for such period as it may think fit, exempt from the provisions of this Act,---
(a) any vessel or class of vessels engaged in coasting trade; or
(b) any class of vessels chartered by a citizen of India or non-resident Indian or an overseas citizen of India, or a company or a co-operative society or a limited liability partnership or such entities as may be specified by the Central Government under sub-section (1) of section 11.