The marriage would take place at the hill station of Panchgani, about 250 km from here, on January one, sources said.
The star has booked an entire hotel at Panchgani for the event, which would be attended by who's who of the film industry, the sources said.
Aamir recently got a divorce from his wife of over a decade, Reena. The actor has two children from the marriage.
The actor was seen in Rao's company at several high-profile functions in the city recently.