<P> The practice of minted coins spread to the Indo - Gangetic Plain from West Asia . The coins of this period were called Puranas, Karshapanas or Pana . These earliest Indian coins, however, are unlike those circulated in West Asia, were not disk - shaped but rather stamped bars of metal, suggesting that the innovation of stamped currency was added to a pre-existing form of token currency which had already been present in the Mahajanapada kingdoms of the Indian Iron Age . Mahajanapadas that minted their own coins included Gandhara, Kuntala, Kuru, Panchala, Shakya, Surasena and Surashtra . </P> <P> The tradition of Indian coinage was further influenced by the coming of Turkic and Mughal invaders in India . The East India Company introduced uniform coinage in the 19th century CE, and these coins were later imitated by the modern nation states of Republic of India, Pakistan, Sri Lanka, and Bangladesh . Numismatics plays a valuable role in determining certain period of Indian history . </P> <P> Punch - marked coins are a type of early Coinage of India, dating to between about the 6th and 2nd centuries BCE . </P> <P> The first coins in India were minted around the 6th century BCE by the Mahajanapadas of the Indo - Gangetic Plain, and certainly before the invasion of Alexander the Great in the 4th century BCE . The coins of this period were punch - marked coins called Puranas, Karshapanas or Pana . Several of these coins had a single symbol, for example, Saurashtra had a humped bull, and Dakshin Panchala had a Swastika, others, like Magadha, had several symbols . These coins were made of silver of a standard weight but with an irregular shape . This was gained by cutting up silver bars and then making the correct weight by cutting the edges of the coin . </P>

How are coins valuable source of information about ancient india