As stated on this site, India is unique in that it has easy sea trading routes to every continent, and is therefore a major trading center. When did India become one— during British occupation, after independence, or during some other period?
India is far from unique in being a major trade center. The author is being very liberal in their definition of "unique".
But India's status as a major trade center is very ancient. As far back as the Bronze Age, there was brisk trade between the Indus Valley and Mesopotamia, sometimes via sea. There are documents from 1st century CE describing India as a major trade destination, linked to Egypt, Rome and China. Ancient trade routes with India included the Silk Road and the Incense Route. When the spice trade became prominent, Columbus tried going West and thought he reached India. India was colonised by many European powers, due to its favourable position for trade.