Kennedy would probably win all those he and McCarthy split, but Johnson, probably through surrogates and favorite sons would hold onto primary states like Ohio and Florida. Johnson, being the incumbent President and all, likely heads to Chicago with a delegate lead, maybe enough of one to give him the first ballot win if RFK can't get enough of the bosses on his side.
Worst? The convention fails to select a nominee for multiple ballots, the confrontations between the Chicago police and the anti-war protestors grow more violent up to and including the staff of anti-war candidates, and it drags on with violence on the convention floor until the Party is figuratively (and maybe literally) burned to the ground and whoever the nominee is, Kennedy, Johnson, a compromise, loses in a landslide in November,
Best Case? Daley is convinced (somehow) to keep things restrained, Kennedy manages to talk the protesters down, you get a calm-ish convention that selects either Kennedy or a broadly amendable compromise pro-peace candidate that enters the general without Chicago as an anchor around their neck.
Most Likely? Probably closer to worst then best, a contest between LBJ and RFK at Chicago, two men whose personal vendettas are far longer then their political ones, is an intra-party bloodbath waiting to happen. LBJ's presence is only going to embolden the protestors, the fact that he's the President is going to further tighten up security measures, and couple it with the willingess and the desire of many police officers to pick a fight, and what you get is a pressure cooker waiting to pop.