Multitenancy with Flowable 6.6.0 with keyclock intgeration

not sure what you mean by upgrading to 6.6.0 with keycloak integration. AFAIK, flowable does not offer keycloak integration out of box, but you should implement your own identity service
here are some useful links about it

while implementing the id-service, you can (and should) map keycloak realm to flowable tenant id, in order to have multitentancy in flowable