hi,

see generally candidates have the roll no and registration no to appear in 12th or any board exam. however you first clarify what they mean about the hall ticket number, if it is same with roll number then you may get it in your 12th exam admit card.

however since around 15 years passed, it is hard to find the admit or exam related details of particular candidate in official site. another option is you may go to  your institution and contact with exam cell and have a discussion to retrieve the data.

hope you understand.