Words with six syllables, if you consider 'y' as a separate syllable:
* Incomprehensibilities: (in-com-pre-hen-si-bil-i-ties)
* Unintelligibilities: (un-in-tel-li-gi-bil-i-ties)
* Antidisestablishmentarianism: (an-ti-dis-es-tab-lish-men-tar-i-an-ism)
Words with six syllables, if you consider 'di' as a separate syllable:
* Indispensabilities: (in-dis-pen-sa-bil-i-ties)
Words with six syllables, using a less common pronunciation:
* Supercalifragilisticexpialidocious: (su-per-cal-i-frag-i-lis-ti-ex-pi-al-i-do-cious)
Other options:
* Pneumonoultramicroscopicsilicovolcanoconiosis: (This word is often mispronounced as having 12 syllables, but it actually only has 11. However, it can technically be pronounced as having 6 syllables by combining certain sounds.)
Keep in mind that the number of syllables in a word can vary depending on its pronunciation and the context in which it's used.
Do you have any particular type of word in mind? Perhaps a specific category or a specific starting letter? Knowing more about your needs can help me find more relevant examples.