There is a chance you might be able to correct your PGCET application data regarding caste and income category,

• Look for any official notification or information on the PGCET website about a window for application corrections.
  
  
• Many entrance exams allow corrections for a limited period after application submission.
  
  If you find no information about a correction window, contact the PGCET helpline or email address provided on their website. Explain your situation and inquire about the possibility of correcting your caste and income category details.
  
  If there is a correction window, be prepared to submit any supporting documents required. This might include your caste certificate and income proof (documents showing your family income is below 8 lakhs annually).
  
  If application correction isn't possible, you might have to consider submitting a new application (if allowed) with the correct information. This could lead to additional fees and a delay in processing your application.
  
  https://university.careers360.com/exams/appgcet
  
  I hope it helps!