Its a concept of deemed prospectus..please make me understand it in simple language

For the purposes of this Act, it shall, unless the contrary is proved, be evidence that an allotment of, or an agreement to allot, securities was made with a view to the securities being offered for sale to the public if it is shown— ( a) that an offer of the securities or of any of them for sale to the public was made within six months after the allotment or agreement to allot; or ( b ) that at the date when the offer was made, the whole consideration to be received by the company in respect of the securities had not been received by it.