The (typically open) reed transfer must close by waving a magnet across it, finishing the circuit. The 6v solenoid lock ought to pull inwards allowing the door to be opened. When the magnet is removed the reed transfer ought to open. If you are giving it the rated voltage and it isn't operating, you then likely aren't able to deliver sufficient modern-day. 9v batteries have a high inner resistance, and so cannot offer plenty contemporary. You could put 4 aa batteries in series to get 6v and it can supply plenty extra.