The actor-turned-producer reportedly made the proposal because the movies are both part of the "new age cinema genre", Mid Day reports.
A source told the tabloid: "Ekta was pleasantly surprised when she got Aamir's call. She's a huge fan of his work and has always looked up to him.
"He felt that both the films represent the new age cinema genre. Even though the subject matter of the films is different, they both agreed that the films would bridge a common audience."
Delhi Belly depicts the complicated love lives of three bachelors living in the Indian capital, with the dialogue primarily in the English and Hindi hybrid known as Hinglish.
Kapoor's film has been described as sensual ghost story taking place in "real time" about a couple who escape for a dirty weekend and find themselves trapped in a Big Brother-like situation.
Her work has been described as "pathbreaking" by fellow producer Karan Johar.