mdm mode. cant download

i have a samsung tab t561. it is a collage study tab, where they have their study materials in them. they cannot use it for any other purpose. i wanted it to go to stock mode. when i tied to flash it with stock rom , with odin and some software box, i always get the error as MDM MODE. CANT DOWNLOAD

can u plz put some light as to how to disable the mdm mode or how to load a stock rom on this?