Help !!!No O.S. Installed!!! Samsung Galaxy Tab A 9.7"

Went to wipe the tablet of any junk files and somehow managed to wipe the O.S. Off it as well. I've tried using Odin to reinstall a stock O.S. but have been unsuccessful in doing so. Can somewalk methrough this please? I've been without my tablet for almost a full month now. Thanks to all!!!