The Tara depicted in this brass statue is Green Tara. Green Tara is usually pictured seated on a lotus throne, right leg pendant with foot supported by a small lotus. Her right hand is in 'charity' mudra and her left in 'argument' mudra.
Tara is the central female deity of Tibet. As a bodhisattva, she blesses and saves those who pray to her. The faithful may appeal to her directly without the intermediary of a lama. Tara is considered the mother of all buddhas and bodhisattvas. She is incarnate in all good women.
Tara may have a mortal precedent in the Nepali princess who married the great king Srang-Tsan Gampo. He is credited with helping introduce Buddhism to Tibet and China.