Weight and script lead to think to a mughal dam. I read "zar(b) Peshawa(r)" + something at 11 o'clock? unfortunately the other face isn't easily readable..
This mint is a very scarce mughal mint, only recently recorded for rulers from Shah Jahan to Muhammad Shah (for silver or copper? I don't know)
The std of the dam was reduced by Aurangzeb, however dams of 20-20,5g are known for him and for Shah Alam I; so if it's well Peshawar, the ruler for such a dam should be Shah Jahan, Aurangzeb or Shah Alam I. (later issues weigh +/- 14g)
It's only a suggestion which needs confirmation.
