If you've lost your hall ticket number, there are several steps you can take to retrieve it:

1. **Check Your Email/SMS**: Many institutions send hall ticket details via email or SMS when you register for the exam. Search your inbox or messages for the registration confirmation or hall ticket details.

2. **Visit the Official Website**: Go to the official website of the exam or institution where you applied. They often provide a way to recover or download hall tickets by entering details like your registration number, date of birth, or email ID. Some websites have a "Forgot Hall Ticket Number" option.

3. **Contact the Exam Authority**: If the website doesn't help, you can contact the exam authority directly via their helpline or email. Provide them with your registration number and personal details to retrieve the hall ticket.

4. **Check with Your School/College**: If you applied through your school or college, they may have a copy of your hall ticket number. Contact the exam coordinator for help.

5. **Social Media/Online Forums**: Check if other candidates have faced the same issue. Sometimes, forums or groups related to the exam can offer guidance or direct links for recovery.

These steps should help you retrieve your hall ticket number effectively.

hope this helps you!!