Section 211(5)(b) in The Tamil Nadu Building and other Construction Workers (Regulation of Employment and Conditions of Service) Rules, 2006
(b)on an application made by any party to the enquiry, the authority or the enquiry officer, as the case may be, referred to in sub-rule (1), if it or he is of the opinion that the holding of public enquiry will lead to disclosure of information relating to a trade secret, decides to hold the enquiry of such part of it is in camera, such enquiry shall not be held in public.