New Mutants are a superhero team from the landmark comic series of the same name which spun off the X-Men in the 1980s, following students of the Xavier Institute who were not members of the X-Men. It was notable for being much weirder than preceding X-Men comics, and classic runs written by Chris Claremont and Louise Simonson are essential reading.
The New Mutants is a film adaptation based on the above which was produced by Fox before they were bought by Disney. The film has been finished for about 2 years but release dates kept being postponed for a few reasons, one of which being nobody wants it.