if your sister’s AIIMS exam payment failed even after trying multiple times, the first thing is to call the AIIMS exam helpline at 1800-117-898 (available Mon–Sat, 9:30 AM–6 PM). If that doesn’t help, you can also email the Examination Section at ace.aiims@gmail.com or examinations@aiims.gov.in to explain the issue. Make sure to mention your registration ID, payment reference, and take screenshots if any. They usually respond and guide next steps.