Rao completed her PhD in high energy physics in the sub-field of grand unified theories. After holding postdoctoral positions at Fermilab and at the University of Wisconsin–Madison, she joined the Institute of Physics, Bhubaneswar in 1987. She made the crucial decision to shift her field of research to theoretical condensed matter physics from high energy physics upon finding that her achievements were being belittled, and her work and papers attributed to her husband Ashoke Sen who was working in the same field. Much of her training in high energy physics and contacts abroad would no longer be useful and she would have to start all over again.