Karan, who is presenting the film, said he was all excited to walk the red carpet with the entire team but unfortunately he would not be able to reach Toronto.
"I am very upset about it, but nothing is in my hands because I can't overlook prior commitments. I have to be in Durban before heading back for the finale shoot of a dance show. But I am always there with the team in spirit.
And also, I will be part of the promotions throughout India," Karan said. "Lunchbox" stars Irfan Khan, Nawazudin Siddhiqui and Nirmat Kaur. The film, which bagged the Critics Week Viewers Choice Award at the 66th Cannes Film Festival in May this year, hits theatres in India on September 20.
Spotted: Sangeeta Bijlani at store launch in Bandra
Photos: Ajay Devgn and his girl gang promote 'Shivaay'
Irfan Pathan's birthday: Popular brother duos in international cricket
Kumar Sangakkara birthday: Batsmen who hit the most Test double tons
Birthday special: 21 actresses who married businessmen