Five punch-mark symbols / Small bankers' mark. Irregular flat silver planchet, 17mmx17mm, 3.46 grams. Gupta/Hardaker ISPC series IV XXXI D (#406-408).

With only four punchmark - the fifth was omitted, probably in error. Very rare with 4 punches only (instead of the normal five). 

The Nanda Empire originated from the kingdom of Magadha in Ancient India during the 5th and 4th centuries BC. At its greatest extent, the Nanda Empire extended from Bengal in the east, Punjab in the west and as far south as the Vindhya Range.