This is Vedanta Desika, a Vaishnavite guru from South India. He is a historical figure and lived in the 13th/14th century. He is a poet, philosopher and master teacher. Vedanta Desika upheld the concepts preached of Ramanuja.
Here in this bronze, he has Vaishnavite markings on his forehead and chest. His right hand is showing a combination of Abhaya and chin mudra. He is holding palm leaf manuscript in his left hand.
So far I have not come across any literature that details of Vaishnavite saints iconography. Here the identification is based on the cover page of the book on Sri Vedanta Desika by M Narasimhachary.
This bronze is about 6.5 cm in height. The quality of detail is remarkable for a bronze of this size.
There are some signs of handling or ritual wear and patina is deep. This bronze may date to the nineteenth century.