Here are the latest advertised appearances for The Undertaker, Triple H, Brock Lesnar, The Rock and Chris Jericho for before and after Wrestlemania.
March 25 RAW (Philadelphia, Pa.): The Rock and Chris Jericho
March 26 SmackDown (Hershey, Pa.): The Rock and Chris Jericho.
April 1 RAW (Washington, D.C.): Undertaker, The Rock, Triple H, Brock Lesnar, and Chris Jericho. (The TV taping time will be pushed up to 6:30 PM ET to tape portions of the final Smackdown before Wrestlemania.)
April 8 RAW (East Rutherford, New Jersey): The Rock and Chris Jericho
April 9 SmackDown (Boston, Massachusetts): Triple H, Chris Jericho (John Cena is also scheduled)
Chris Jericho currently doesn't have a WrestleMania match but is expected to be added to the card soon, possibly against Fandango.