Desi version of American thriller series "24", it comes on Colors on Friday and Saturday.
"It's terribly exciting to be part of a project like this, of course! I was a huge fan of the original '24' and the Indian version has emerged as a game changer for TV here. I'm so proud to be part of it," Khanna told in an email interaction.
He will enter as an investment banker, whose name crops up during investigations by protagonist Jai Singh Rathod, played by Anil Kapoor, who is also co-producing it.
Rahul said that he always harboured a desire to play a mysterious character, something close to what he plays in the show.
"I've always wanted to play a character with an air of mystery and shades of grey and I must say, although it was a difficult shoot (long shooting days and a tough action sequence filmed in the middle of the Bombay monsoon), but a lot of fun to do," he said.
While many value the length of screen time, Rahul attributes more significance to the kind of role he gets to play.
If he played important roles in movies like 'Earth' and 'Hollywood Bollywood', the actor did cameos in commercial movies like 'Love Aaj Kal' and 'Wake up Sid'.
"It's not so much about the length of the role, but rather its importance in the narrative and getting to be a part of an exciting project. If the role has the potential to make an impact, the length makes little difference," he said.
The 41-year-old is in pursuit of new genres.
"There's nothing I love more than acting in films. I am always on the lookout for new, exciting projects...
"For me, part of the joy of being an actor is the opportunity to work in as many different genres as possible. I look forward to being part of more full-blown commercial films as well as more independent ones," he said.
The actor disagrees with the general opinion that he has not done too many commercial films.
"Most people think I shy away from mainstream Bollywood cinema but that couldn't be further from the truth. The fact is, I've actually worked with some very masala filmmakers, including producers Raj Kanwar in 'Raqeeb' and directors Vikram Bhatt's 'Elaan'," he said.
On the movies front, the actor is looking forward to the release of his film "Fireflies", "a cool, indie film".
"It's a simple, poignant story about love, loss and redemption. It's set between the present scenario in Mumbai and the tea plantations of Ooty (Tamil Nadu) in the 1980s. It centers around two brothers and a tragic incident from their childhood that has colored their relationship," he said.
Directed by ad-film director Sabal Shekhawat, the film's cast also includes Arjun Mathur and Monica Dogra.