What is this region highly contested between Poland and Lithuania called in Polish where Lithuanian Education Society Rytas is located? 
Lithuanian Education Society Rytas: The Lithuanian Education Society Rytas (Lithuanian: "Lietuvių švietimo draugija „Rytas“" ; "rytas" means "morning" or "dawn") was a Roman Catholic society fostering education in the Lithuanian language mostly in the Vilnius Region, then fiercely contested between Lithuania and the Second Polish Republic, now split between Lithuanian and Belarus.
i don't know