When smiling 8-year-old Indian actor Sunny Pawar says xiaxia nong ("thank you" in Shanghai dialect), it strikes a chord.

One of the youngest stars at the ongoing 20th Shanghai International Film Festival, Pawar is in the Chinese city to promote his film Lion, which will be released across China on Thursday.

The Australian film released in the United States in November 2016 and in Australia in January has won more than 30 film awards and nearly 70 nominations, including for the Oscars and Golden Globes.

The movie, based on the nonfiction book A Long Way Home, is about an Indian-Australian man, who uses the internet to find his birth mother.

He got lost in India when he was 5 and was adopted by an Australian couple in Tasmania, who are played by Australian stars Nicole Kidman and David Wenham.

Pawar stars as the child, while Indian-English actor Dev Patel plays his older version.

Pawar says he was selected for the role from more than 2,000 students.

His natural acting impressed the casting director, who believes the young boy has potential.

"I am happy, as I've done a good job," Pawar says at a Shanghai cinema after the festival screening.

Prakash Gupta, consul general of India in Shanghai, says movies with Indian themes are popular in China, thanks to the phenomenal success of Dangal, the highest-grossing non-Hollywood import into China.

He highlights the similarity between Lion and Dangal, saying: "The first and most important thing is that both of them are based on real stories ... both their themes are common to all of us."

Gupta says he believes the suffering and struggles in the two movies resonate with audiences, making them globally successful hits.

Graeme Meehan, consul general of Australia in Shanghai, also attended the screening. He says Australian movies have gained popularity across the world in recent years.

"I hope in the future we'll see more Australian films in China," says Meehan.