Nykaa, an omni-channel retailer of beauty products, could well be on its way to become the next billion-dollar Indian company. The Mumbai-based start-up has raised Rs 100 crore from private equity firm TPG Growth at a valuation of $724 million, company filings sourced from business intelligence platform Paper.vc, showed.   This means, in just six months, the company’s valuation has more than doubled. In September 2018, when Lighthouse Advisors invested Rs 113 crore to buy out early investor TVS Capital, Nykaa was valued at $330 million. Avendus Capital advised on this deal. Earlier, in 2018, the start-up had also raised Rs 160 crore through primary and secondary share sale.