What does "fix one's charges" mean?
To answer this question, it's important to give context to the scene. Cobb (DiCaprio) has been charged with the murder of his wife. He did not commit this crime because his wife committed suicide and wrote a note saying that he did it. When he says "fix one's charges" he means that these people have special connections that could remove the murder charges against him. It isn't really common to say "fix my charges." A more common way to say it would be "remove my charges."