Ranaut was declared the winner for her endearing dual turn as Tanu, a troublesome wife and Haryanvi sportsperson Datto in romantic comedy "Tanu Weds Manu Returns".
The actress, who turned 29 last week, called it the "best birthday gift" especially since she gets to honour with Bachchan.
"It is the best birthday gift I could have got. I am thrilled and feel blessed especially since Mr Bachchan is the best actor with me," Ranaut said in a statement.
This is the third trophy for Ranaut at the National Awards, having won best actress for "Queen" last year and earlier for best supporting actress for 2008 film "Fashion".