"Pahuna" ("The Little Visitors") revolves around three Nepali children who get separated from their parents, escape the Maoists agitation in Nepal and flee to Sikkim.
The film has been directed by Paakhi Tyrewala.
The actor took to Instagram to share a video from the screening and said she is proud of the movie and the director for not giving up the idea to make this film.
"Never be ok with hearing the word no... Because there will always be someone who will say 'yes'. I'm very proud of my first time 'female' director @paakhi for having the courage to not give up, when people didn't believe this film could be made," Priyanka wrote.
The actor also thanked her mother, Madhu Chopra, and TIFF's artistic director Cameron Bailey for giving her an opportunity to share this "small film and a big message with a world audience... One about children's rights, the refugee crisis, religious conversion".