If a candidate finds any error in the JEE Main admit card, such as incorrect name, photograph, date of birth, category, or exam center details, they should immediately contact the National Testing Agency (NTA) through the official helpline or email support mentioned on the website. Candidates should report the issue as soon as possible so that corrections can be made before the exam date. In some cases, candidates may be allowed to appear for the exam with the incorrect admit card but must provide supporting documents for verification. It is important to check the admit card carefully after downloading it to avoid complications on the exam day.