(3)For the purposes of sub-section (1) or sub-section (2), an assignment of a design or of a share in a design, a mortgage, licence or the creation of any other interest in a design shall not be valid unless the same were in writing and the agreement between the parties concerned is reduced to the form of an instrument embodying all the terms and conditions governing their rights and obligation and the application for registration of title under such instrument is filed in the prescribed manner with the Controller within six months from the execution of the instrument or within such further period not exceeding six months in the aggregate as the Controller on the application made in the prescribed manner allows:Provided that the instrument shall, on entry of its particulars in the register under sub-section (1) or sub-section (2), have the effect from the date of its execution.
