(6)In the event of the issuing company or the underwriters to the issue have invited or received advance subscription by way of cash or post-dated cheques or stock-invest, the company or such underwriters or bankers to the issue shall not encash such subscription moneys or post-dated cheques or stock-invest before the date of opening of the issue, without having individually intimated the prospective subscribers of the variation and without having offered an opportunity to such prospective subscribers to withdraw their application and cancel their post-dated cheques or stock-invest or return of subscription paid.