The gossip mills are abuzz that the couple, who began dating last year after starring in "Alone", is set to tie the knot in April.
While this would be Bipasha's first marriage, Karan has been married twice earlier.
When asked about the rumours, Bipasha, 37, told reporters here, "When it will happen, you all will get to know."
The actress was in the capital to inaugurate a showroom of watch brand Seiko.
On being asked about the importance of time in her life, Bipasha said, "Time is the biggest luxury for me. I lead a very disciplined life and for that value of time is very important."
More From This Section
"I love myself. I love the life God has given me. I want to stay beautiful. The whole social stigma that we have about women aging... I have that's changing now.
"You have to embrace each year and for that you have to invest in workouts, eat healthy and lead a disciplined life. I think the best investment in life is health investment," Bipasha said.
Though the actress was one-hour late at the event, she called herself "a very punctual" person.