The process of applying for PGCET (Post Graduate Common Entrance Test)  with a closed school from your 1st to 5th standard can vary depending on the specific PGCET exam you are applying for.

• First, identify the specific PGCET exam you are applying for. Different states or universities might conduct PGCETs with varying eligibility criteria.
  
  
• Locate the official website of the exam authority conducting the PGCET.
  
  
• Look for sections on "Eligibility" or "Documents Required." These sections should detail the mandatory documents and might mention any specific requirements regarding certificates from closed schools.
  
  
• In most cases, a study certificate issued by the school when it was operational should be considered valid proof of your education during that period.
  
  
• However, some PGCET authorities might request additional documentation to verify your studies.
  
  
  
• Reach out to the exam authority through their helpline number or email address mentioned on the official website.
  
  
• Explain your situation regarding the closed school and inquire if the old study certificate is sufficient.
  
  
• Ask if any additional documents are required to verify your early education.
  
  
  
• If you have a leaving certificate from the closed school, mentioning the duration of your attendance, present that as well.
  
  
• As a last resort, you can get a sworn affidavit notarized by a public notary, stating your attendance at the closed school from 1st to 5th grade.
  
  
• In some cases, authorities might accept verification from the education department or local government records if available for the closed school.
  
  https://www.careers360.com/exams/karnataka-pgcet
  
  I hope it helps!