I don’t know what the report is going to say, but it’s not going to say “no collusion”. There have been too many indictments of Russian operatives and Trump officials for that. The best the Republicans can hope for that Mueller will not have enough evidence to indict Trump himself. Barr has already implied that he’ll only allow parts of the report that deal with actual indictments to be released to the public. Evidence gathered against Trump then will never see the light of day, and the GOP will claim the non indictment as proof of Trump’s innocence.