The competent [authority] [For appointment of D. General Manager, NCDC Ltd., as competent authority for the purposes of Sections 4(3), 6, 12, 13(6) and 22] may, by notice in writing, require any person in possession of any land acquired under this Act to surrender or deliver possession of the land within such period as may be specified in the notice, and if a person refuses or fails to comply with any such notice, the competent authority may enter upon and take possession of the land, and for that purpose may use or cause to be used such force as may be necessary.