How did Indian entrepreneurs accumulate capital for investment?

Many Indian entrepreneurs earned huge capital from China trade- the trading of opium to China and taking tea from China to England.
The Company employed many Indians as junior players in this trade. Having earned some wealth businessmen had vision of developing industries in India.
In Bombay, Parsis like Dinshaw Petit and Jamsetjee NusserwanjeeTata accumulated initial wealth partly from exports to China and partly from raw cotton shipments to England. Capital was also accumulated through other trade networks.