The film, along with a memoir that is still in its early stages — Mr. Tyson is collaborating with the author Larry Sloman, who has ghostwritten autobiographies for Howard Stern and Anthony Kiedis, the lead singer of the Red Hot Chili Peppers — are two parts of an effort that Mr. Tyson’s advisers hope will reintroduce him to the public and propel him to some semblance of a postboxing career.