The 28-year-old actress wore denim hot pants teamed with a broad belt, knee-length boots, a cropped yellow top with a black leather biker jacket and gloves for the first promo, a statement said.
Her look has been created by Bollywood stylist and fashion designer Anaita Shroff Adajania, who earlier styled for the "Dhoom" franchise as well as "Race".
Priyanka was in Bangkok recently to shoot the promo.
The first look is expected to air on the channel early next week. It shows Priyanka in a chase sequence on bikes with male bikers.
"Khatron Ke Khiladi 3" will have 13 male celebrities competing against each other on dangerous tasks in Brazil.
The last two seasons of the show were hosted by action star Akshay Kumar.