I know nothing about the Tatas' origin, although it's hard to miss the importance of the modern Tata Group. Wikipedia says that the family fortune was founded by Jamsetji Nusserwanji Tata, who had some wealth from his father Nusserwanji and parleyed it, through trade, into enough capital to recondition a cotton mill.
Are you saying that Jamsetji's trading company dealt in opium? That his father's business was involved in it? Or even both? If so, looking at things from a United States perspective, I'd find that a little heartening. I'd always seen the opium trade as a matter of pumping money from undeveloped China to already-rich London and Boston; if there was going to be an opium-for-silver trade regardless, at least some of the silver went to somewhere else in need of capital.