Source: WrestlingNews.Co 
Here are some details of the format for the WWE Raw 25th anniversary show on January 22nd. 
The Manhattan Center portion of the show is only scheduled to run from 7:30 pm to 9:00 pm for fans in attendance. This is according to information provided by the Manhattan Center box office. That would mean that the first hour of Raw would air from that venue and the remaining portion of the show would air from the Barclays Center. It looks like the fans at the Barclays Center (show starts at the regular 7:30 pm start time for them) will get dark matches while fans at home are watching the Manhattan Center portion of the show.

Most of the legends are scheduled to appear at the Manhattan Center. This is also the go-home show for the Royal Rumble so I would expect that the major angles will probably take place at Barclays.
Names scheduled to appear on the show include The Undertaker, DeGeneration X, Jim Ross, Jerry “The King” Lawler, The Dudley Boyz, Ric Flair, Scott Hall, Kevin Nash, The Bella Twins, The New Age Outlaws, The APA, Ted DiBiase, Eric Bischoff, and Stone Cold Steve Austin. I believe Mick Foley and Bret “The Hitman” Hart are also expected to be on the show. Also, Roman Reigns will defend the Intercontinental Championship against The Miz and we’ll see the return of Brock Lesnar and John Cena.