Report to the invigilator or centre superintendent immediately — do not argue with the staff.
Carry your original photo ID, since manual verification is done when biometrics fail.
Mismatch can happen from worn fingerprints, henna, cuts or dusty scanners — keep fingers clean and dry.
Many exams use Aadhaar-based verification, so ensure the details in your form match your Aadhaar.
Repeated failures are recorded, but genuine candidates are allowed in after manual checks.
If your biometrics are permanently unreadable, inform the exam helpdesk well before exam day.