Has the (highly possible 46th POTUS) Joe Biden told anything about or hinted whom may he include in his cabinet? If it is not declared (most probably) when may he declare it?
It would be highly unusual for a President-Elect to have named his Cabinet before he is deemed elected. Usually these announcements will be made starting mid-November and continue through to January.
For reference, President Trump made his first Cabinet announcement on November 18, 2016, naming his picks for Attorney General and CIA Director, and he made his final pre-inauguration Cabinet announcement (Agriculture Secretary) on January 18, 2017.