Sonam, 29, who worked with Omprakash Mehra in 'Delhi 6', said her brother met Mehra on the sets of the 2009 film.
"I am in the industry for seven years and I have never seen someone working so hard. He is very dedicated towards the art. I think he is very lucky to do a film with Rakeysh.
"I know Rakeysh on a personal level and he met him on the set of Delhi 6. But he did it on his own. He kept on calling Rakeysh with the intention of working with him," she said.
In the film, Harshvardhan will be seen playing the titular role of Mirza.
The 'Dolly Ki Doli' actress said he has a long way to go and if he has luck with him he will be the next star.
"Harshvardhan is a couple of years younger to me. He is good looking. According to me, hard work can take you places but in this industry you need both hard work and luck. So, my brother is ridiculously hard working. He takes that into a different level. And I wish he has the bit of luck also," she added.
Sonam and Arjun are the most popular actors of the Kapoor clan besides Anil and Sanjay. She will be next seen in Arbaaz Khan's 'Dolly Ki Doli' as a runaway bride. The film will hit theatres on January 23.