The six syllables associated with him are the most-recited formula in the Buddhist world, and two things about them are worth setting straight.
The first is the translation. The English rendering the jewel in the lotus is grammatically wrong. Read as a compound, manipadme would have to be a vocative addressed to someone called Jewel-Lotus, and the form is feminine, which points to a female figure, most plausibly a consort, rather than to Avalokiteshvara himself. This has been argued in detail by Sanskritists and is not a fringe position. The devotional readings the tradition supplies are different again: Tibetan commentary maps the six syllables to the six realms of rebirth and to the six perfections, and treats each as purifying a particular affliction. That is a religious reading, offered as one, and it does not depend on the grammar.
The second is access. Much Vajrayana practice is closed: the mantra of a specific meditational deity comes with the empowerment that authorises the practice, and reciting it without that is regarded within the tradition as ineffective at best. The six-syllable mantra is deliberately outside that system. It is carved on roadside stones, printed on flags, turned in wheels, and taught to anyone. Tibetan teachers say plainly that it requires no permission.
The distinction between open and closed mantras is a real feature of the tradition and not an accident of what happens to have been published. Confusing the two, assuming that because this one is public, all of them are, is the commonest Western misunderstanding of how the material works.