jurisdiction

ao passed without addition 143(3) without territorial jurisdiction. pcit set aside the assessment under 263 and directed to make reassessment. the reviewing authority (range head) or pcit has not noticed and/or mentioned anything about the jurisdiction issue. assessee has not challenged jurisdiction during assessment as well as 263 proceedings. there may be addition on reassessment. suspect the assessee may challenge jurisdiction issue in reassessment and/or appellate stage. what will happen ? what is the remedy ? is there any section in it act or case law in favour of dept ?