The vast majority of people in India, the world’s second most populous nation, don’t have health insurance coverage. A significant portion of the population that does have coverage get it from their employers. Plum, a young startup that is making it easier and more affordable for more firms in the nation to provide insurance coverage to their employees, said on Monday it has raised $15.6 million in its Series A funding to accelerate its growth. Tiger Global led the new funding round, with participation from existing investors Sequoia Capital India’s Surge,…