This curved plaque would have been bound to the upper arm, as a protective, talismanic. It has eight loops around its sides to allow this. It could also be worn as a pendant. Probably it would have been worn by a Hindu Vaisnava priest.
The plaque has been cast with a central figure of Vishnu in the deity’s rare, meditative form. Surrounding this are various diminutive deities as well as a pair of Vishnupada – Vishnu’s footprints which we were worshipped in their own right and as stand in for the deity.
See van Cutsem (2002, p. 214) for a related example, and Bussabarger & Dashew Robins (1968, p. 116) for another.
The example here has obvious great age and wear.
References
Bussabarger, R.F. & B. Dashew Robins, The Everyday Art of India, Dover, 1968.
van Cutsem, A., A World of Bracelets: Africa, Asia, Oceania, America, Skira, 2002.