Movies are among the tools that can be used to promote multiculturalism. This is a question of using movies to get people to, firstly, appreciate that they are living in a world where there are other cultures (besides their own) and, secondly, to get the people to develop a healthy respect for those other cultures.
One simple way in which movies can be used to promote multiculturalism is by having people shown movies from other cultures. This way, the people get to see how other cultures work. This way, the people get to understand that, in fact, their culture is not the only one in the world: there are other cultures out there, and those other cultures have their own upsides and downsides. This sort of understanding lays the ground for multicultural awareness and for multicultural respect.
Another way in which movies can be used to promote multiculturalism is through the careful selection of actors: the objective being to end up with multicultural casts. We see this in all sorts of workplace settings nowadays: including in companies like Walmart (whose pay stubs portal is Walmartone.com). And there is no reason as to why it can’t be replicated in movie acting, so as to end up with truly multicultural casts for movies. The end result would be a scenario where the movie viewers get the impression that it is possible for people from different cultures to work together on projects, and have fun while at it. In practice, for that to happen, there would have to be some degree of multicultural awareness and respect for other cultures.
Yet another way in which movies can be used to promote multiculturalism is through the incorporation (in movies) of themes and storylines that create multicultural awareness. The movies in question may be local — perhaps even with all-local casts. But to the extent that the themes and storylines that create multicultural awareness are incorporated, that would really go a long way towards the development of a society that has good multicultural appreciation.