Since you are a PCB (Physics, Chemistry, Biology) student, you should inform the KCET authorities about the mistake in your admit card. It may have automatically been set to the PCMB (Physics, Chemistry, Mathematics, Biology) category, which could affect your exam and ranking. Here are a few steps you can follow:

1. Contact KCET Helpdesk or Authorities : Reach out to the official KCET authorities or helpdesk immediately to correct the admit card. They should be able to resolve the issue, as your eligibility is based on PCB subjects.

2. Skipping the Maths Exam : If the admit card is showing PCMB, it means they expect you to take the mathematics exam along with Physics, Chemistry, and Biology. However, if you are a PCB student and decide to skip the mathematics exam, it will not affect your ranking in the PCB category.

Important : You need to confirm with the authorities if skipping the maths exam will disqualify your candidature or affect how your results are processed.

Make sure to clarify the situation before your exam so that there are no complications with your ranking or eligibility.