 Her last major movie was "The Man Who Knew Infinity" (2016), in which she played the mother of the mathematical wizard Ramanujan.She has also appeared in Hindi movies including "Paa" (2009), "Sapnay" (1997) and "Dil Se" (1998), Kannada movies including "Golibar" (1991), "Jogi" (2005) and "Andar Bahar", and Malayalam "Da Thadiya" (2012)

Nag was born in 1956 in Delhi, stayed in Netaji Nagar.Her family moved to Mumbai when she was 10.