Assessee-trust was formed with an object of running a hospital and research centre. It was granted registration under S.  12A in year 1979 and since then assessee had been claiming benefit of exemption prescribed under s. 11 and 13 of the Act. Subsequently, Commissioner took a view that manner of investment of trust funds was in violation of provisions of S. 13 of the Act. Accordingly cancelled the registration. On appeal the Tribunal held that , violation of provisions of S. 13 empowers an assessing authority to forfeit exemptions permissible under S. 11 and 12 but such a violation cannot form a ground to cancel registration by passing an order under S.12AA(3) of the Act.