Based on the posture and hand mudra's, this figure most probably represents the Maitreya or the bodhisattva of the Future. It is known that the Maitreya was one of the most popular bodhisattva during this early phase of Chinese Buddhism.
This figure is similar to other figures of Maitreya Buddha dated to the Northern Wei period and thought to come from the Longmen caves. For a similar example see the Norton Gallery, West Palm Beach, Florida, and illustrated in A Handbook of the Chinese Collections, 1972, no. 103, where figures of this small size are described as being carved in the spaces between the larger figures arranged in niches around the walls of the caves at Longmen. Two other examples from the Guyang Cave are published by O. Siren in Chinese Sculptures in the Van de Heydt Collection, Rietberg Museum, Zurich 1957, pls. 11 and 12.