Original sentence: The Dalai Lama is the spiritual leader of many (though not all) Tibetans and head of the Tibetan Government in Exile  in Dharamsala, India and exerts a powerful influence over the the Gelug School of Tibetan Buddhism
Edited sentence: The Dalai Lama is the spiritual leader of many (not all) Tibetans and head of the Tibetan Government in Exile  in Dharamsala, India and exerts a powerful influence over the the Gelug School of Tibetan Buddhism