This is one of the leaves of Mandala. For an example of Mandala, please see the Jain Mandala on this website.
The central figure of this mandala might be a Vaishnavite figure. An example of such Mandala is in Ashmolean museum ( Figure of Vishnu in the lotus, Accession no: EAX 285). The Ashmolean bronze is dated to the twelfth century.
The Mandala leaf shows Vishnu seated on Garuda, his vahana. Garuda, in avian form, spread out wings and Vishnu’s feet are supported by Garuda’s wings. This form of Vishnu is often referred to as Garudasana. There is another example of Garudasana on this blog. Vishnu’s attributes are worn out for us to identify them.
See the patterns on the back.
This copper-rich bronze is from eastern India (Bihar/Bengal) or Nepal. This may date to the sixteenth century, if not earlier. The bronze is about 10 cm in height.