I fully agree with Madhu TK. However, while covering the establishment under the Payment of Bonus Act, 1965, the labor department looks for the basic objectives of the charitable institution. If the objectives are entirely for charitable purposes, i.e., on a no-profit-no-loss basis and for the downtrodden of society, you may get an exemption from the department. This I am telling you out of my own experience where a case was filed by the union against a charitable hospital under the Bonus Act, and the management won the case only based on "the objectives of the charitable institution."
Regards.