PWInsider has reported that Undertaker is scheduled to be in north Jersey for WrestleMania weekend, which they've confirmed with "multiple sources".
Currently, there is no confirmation that he will appear on camera at WrestleMania in any capacity, but he is in fact in the area for the weekend.
Undertaker has not wrestled since Crown Jewel on November 2 in Riyadh, Saudi Arabia, where he and Kane lost to Shawn Michaels and Triple H in the main event of the show.
The WWE icon wrestled in 26 of the last 28 WrestleManias (10 and 16 excluded, due to injuries), amassing a record of 24-2 over that stretch. His most recent WrestleMania bout saw him defeat Cena in under three minutes, amounting to a high-profile squash match.