Immortals are not always in sync with player/empoweree times. An approach that may work is to write an in-game note to the immortal in question and/or an email. Either is acceptable.

Often folks seek empowerment at a pretty early age, and their times do not mesh with the immortal, so it may take longer than hoped for a response. Also, be sure the immortal is active...for that you can check the WIZLIST or pray and ask. Additionally, you could seek out any known or marked followers of the immortal and speak with them for some informantion.