Rekha, 59, has often distanced herself from giving interviews and from appearing in chat shows. The actress had, however, once appeared in a candid TV interview with Simi Garewal.
"I would love to interview Rekha. It would be lovely to speak to her as I have never had her on my show. I think this is the right time and it will always be an honor to work with her or to interview her," said Karan.
For now, the first guest of the fourth season of Karan's show will be Salman Khan, and the filmmaker has been a "great season opener".
"Salman has never been on the show. He is wonderful when he speaks honestly. Salman never pretends anything that he is not, and I think candidness and honesty is something required for a show like 'Koffee With Karan'," Karan said.
"You will see Salman like never before...It was great interviewing him," he added.
Karan believes Bollywood stars get up, close and personal with him comfortably as they share a good rapport with him. That is also why it becomes easier for him to ask questions, sometimes even controversial ones.
"I think I know them (stars), so they have a comfort zone with me and it becomes easier for them to answer and it becomes easier for me to ask. I have never done a show doing any research. I never look at anything while asking. It's just spontaneous," the 41-year-old said.
'Koffee With Karan'will be aired on Star World.
His journey on the show has been "fantastic", he said.
"It's been nine years, nearly a decade. It's been a very large part of my personality," said Karan, who first brought the show to the small screen in 2004.