Hello Parth,

GUJPGCET eligibilty criteria states that:

• Candidate should have Passed the qualifying exam in the relevant B.Tech discipline (mentioned in the table below) with 50% marks (45% for SC/ST/SEBC candidates)
• Secured  qualifying marks in GATE in the relevant discipline for engineering

Acc to this you cannot be eligible unless and untill you pass your B.E discipline , which i dont think is possible without clearing backlog , so yes you can apply but if you fail to clear your backlog your admission will be cancelled.

Hope this helps