Watch Nalla Thanka (1950) : Full Movie Online Free Nalla Thanka , the only sister of Nallannan , the King of Madhurapuri, is wedded to Somanathan , the king of the neighbouring kingdom Ratnapuri. Alankari, the wicked wife of Nallannan becomes envious of the prosperity of Ratnapuri and the happy married life of Nalla Thanka.