Vishnu is one of the three main deities of Hinduism. Here he is standing on his own holding Lotus, Chakra (wheel), Shankha (Conch shell) and Gada (mace). Starting from lower right hand, clockwise. It is interesting to see Satkona (two interlocking triangles) in his Chakra.
Vishnu is called by different names depending on the order in which the attributes are held. In this case, as per Padma Purana, he is Vasudeva. The four attributes mean there are twenty-four combinations and names. These names are special among the 1,008 names by which Vishnu is addressed.
Normally Vishnu is with his consorts, in the same or different pedestals. In this case, the consorts would have been on separate pedestals, got separated.
The back is worked on, as it is with South Indian bronzes, though in a normal scenario the back of the deity is never seen. The bronze has been repaired, rather crudely, as seen in the back view.
This Vishnu is from Kerala. The upright prongs from the base to attach prabhavali is typical of Kerala. In bronzes from other South India regions, the prabhavali has prongs and that is inserted into slots in the base, peetham. It is from the 19th century. It is about 24 cm tall.