Section 10(23C)(iiiae) in The Income Tax Act, 1961
(iiiae)any hospital or other institution for the reception and treatment of persons suffering from illness or mental defectiveness or for the reception and treatment of persons during convalescence or of persons requiring medical attention or rehabilitation, existing solely for philanthropic purposes and not for purposes of profit, if the aggregate annual [receipts of the person from such hospital or hospitals or institution or institutions do not exceed five crore rupees.]