There can't be a 6 way tie, only 5 teams can tie on 3
If BBL TH KC VIT and KOI tie on 3-6
BBL +2 VIT +2 TH +1 KC -1 KOI -4
For this situation to happen TH would have had to lose to KOI and beat VIT so the 3-6 would happen which means:
If TH beats VIT 2-0 and lose to KOI 2-1 then it's 2 way tie between BBL and TH on +2 so round differential against the other 4
If TH beats VIT 2-0 and lose to KOI 2-0 then It's BBL +2 TH +1 VIT 0 so BBL make it through
If TH beats VIT 2-1 and lose to KOI either 2-0 or 2-1. Then BBL +2 VIT +1 and TH +1/0 so BBL make it through