Approval under section 35(1)(ii) grants tax-recognition to a research institution for a specified two-year effective period. Approval is granted to Birla Institute of Scientific Research, Calcutta by the prescribed authority under clause (ii) of sub-section (1) of section 35 of the Income-tax Act, 1961, formalised by notification S.O.2196 dated 19-5-1979; the approval is effective for two years from 1-4-1979 to 31-3-1981.