What facts indicate the development of trade and exchange in ancient India?

First of all, this is evidenced by the finds of goods clearly foreign in origin (including those from Ancient Sumer). as well as finds of trading weights, personal seals, traces of harbors, granaries, etc. Excavations of ancient cities also indirectly testify to the same. Unfortunately, the writing of the most ancient civilizations of India (Mohenjo-Daro and Harappa) has not yet been read, therefore, we can only judge the specifics and scale of trade – domestic and with other countries – from the evidence of material culture.