Ratan Tata, the Chairman Emeritus of Tata Sons, is the only Indian investor in Chinese smartphone maker Xiaomi, according to its IPO filings. Tata picked a 0.0024% stake (49,583 shares) in 2015 through his Singapore-based company RNT Associates International. His stake could be worth $2.1 million now based on Xioami's estimated valuation of over $90 billion, according to Bloomberg Quint.