6. Security.- (1) If reasonable grounds exist to believe that it is necessary in the interest of revenue so to do, the Circle In-charge may, for reasons to be recorded in writing, require a dealer to furnish security which shall ordinarily be equivalent to the amount of the tax estimated as being payable by the dealer for a period not exceeding one quarter of any year and for this purpose the Circle In-charge may also consider the requirement of statutory declarations under these rules by the dealer. | 