Hello there,
You need to download your Hall Ticket to get your hall ticket number. Visit the official website and log in to your account using your registration number. There you can download your Hall Ticket. The number will be written on that. You should take a printout of the same.
For more information about the same you can check the link given below:
https://bschool.careers360.com/articles/ap-icet-hall-ticket
Hope this helps you.
Good luck!!

Hi Surya,

If you have the admit card, then the hall ticket number will,be clearly mentioned in it. You can check out the confirmation mail and SMS you must have received after registering for the exam.

If you find this to be of no or little help, I think you should contat the authoritites and let them know. You can find their contact details on the website.

Hope this helps!