From the attributes Chakra, Shankha and Gada (Wheel, Conch Shell and Mace) and the Tarjani mudra (front right hand) it looks like it is Visvakesana, Vishnu’s treasurer and army chief. This blog site has an example of sitting Visvakesana. It is unusual to find a standing Visvakesana.
The other option is it is Dwarapalaka from a Vaishnavite shrine. Ruling out that possibility, Dwarapalaka’s are Guardian deities placed at the entry of the temple and a threatening gesture is out-of-place for the role.
Another aspect to note is the two-tone Ganga Jamuna aspects. It looks like the brass is ‘plated’ on the copper portion. This is the third method, I have come across, to produce Ganga Jamuna vigrahas. The other two methods are placing brass parts into the grooves cut in the base copper Vigraha (See Udupi Krishna), and laying a thin sheet of brass on top of the copper portion that is to be highlighted (See Ganga Jamuna Rama).
We see cold gilding (gold gilding using mercury as the base) in Tibetan sculptures. Not aware of the use of that technique in South India. This Vigraha possibly pre-dates the introduction of electroplating in India, ruling out that possibility. The identification of the techniques used to produce this type of Ganga Jamuna Vigraha needs more research.
This Vigraha is about 15.5 cm in height and it is from North Karnataka. This may be dated to the nineteenth century.