No there is no chance for opening the window to registration second time for PU Cet Panjab University common entrance test for undergraduate courses and PG courses admission registration. Application form for admission has been released on 15th April 2021 the last date of submission of application registration was 18 May 2021. PU CET Exam for UG and PG admission will be held in the month of June 2021.
To know more you can take on the official website of Punjab University common entrance for UG:-ugcet.phcd .ac.in. and for PG admission:-pgcet.phcd.ac.in
Hope this helps.