This is Manjushri, the deity of Wisdom, and one of the more popular Bodhisattvas. Here he is identified by the sword on his right hand and Pustaka resting on the lotus on his left hand. The eyes are inlaid with silver and the religious mark on his forehead is inlaid as well.
Manjushri is wearing a crown, two necklaces and bangles. This slender-waisted Manjushri is wearing a short dhoti and the dhoti inlaid with copper and silver. Not sure as what the long protrusion at the back of the head is meant to signify/represent.
Waist down, other than the decorations on the dhoti, it is bare. No anklets or other foot decorations. The back is not worked on. There is significant ritual/usage related wear, especially on his face. But the features are noticeable.
Standing Manjushri is rarer than the seated ones. Sometimes accompanied by Vajrapani and Padmapani
This idol is about 15 cm in height and it is possibly from Western Tibet. This may date to the 12th century.