Advertisement Income received by Trust

Hi, One of Client is Public Trust. Apart from social activities the Trust is publishing Magazine once in a year. Said Magazine is distributed free. Trust receives certain amount from the persons who place advertise in the magazine. It is not given in the form of Donation, but towards the advertisement put up.Trust incurs printing cost and other cost on it. All the income generated from said would be used towards the object of the trust. Whether said publishing activity would come outside the perview of trust activities? What are the complaince to be made so that it would be under the perview of trust activities?