Section 85 of the Local Govt Act is where the 6 month rule is derived from, but it does allow the rule to be waived if there is good reason. It would be helpful if we knew more here, particularly specific dates. Has the council been holding virtual meetings every month from October 2020? Technically every member of the council ceases to be a councillor at the 10.00 pm close of the poll in May until the returning officer declares who has been duly elected, except for uncontested wards. .However if the principal authority allows somebody to stand for re election, even if they were due to be disqualified, then I would argue the clock is reset to the first meeting of the newly elected members in May 2021.