If an electronic device specifies an operating RANGE between 6~15 volt with 210mA current, can you use a 9 volt battery to power it?
If you connect it with the right polarity it wont damage the unit but it wont last more than some minutes and this depends also on the brand of the battery and its status. Since as it is shown in the following image for a given brand of batteries the voltage will rapidly drop for a current exceeding 50mA: