Section 24(2)(a) in The Orissa Cinemas (Regulation) Rules, 1964
(a)In case of a permanent building - The number arrived at by calculation at the rate of 20 persons per hundred square feet of floor area in respect of such portions as are provided with chairs having backs and arms, and at the rate of 25 persons of floor area in respect of other per hundred square feet of floor area in respect of other portions after excluding the area of the entrances, the passages and gangways, the stage, the stair-cases, and all places to which the public are not admitted.