This is the 18292nd most frequent Russian word.
шестого
"Шестого" means "of the sixth" or "on the sixth" (used for dates).
Here, 'шестого' is used as the ordinal number in the genitive case to specify the date.
Мы встретимся шестого числа.
We will meet on the sixth.
'Шестого' is used to indicate a specific day in the genitive case, modifying the noun 'июня'.
Это произошло утром шестого июня.
It occurred on the morning of the sixth of June.
In this context, 'шестого' is used as a genitive ordinal adjective referring to 'класса,' indicating possession or association.