How do i use policies to route based on certificate attributes.

the documentation is very clear indeed: "Inspects the properties of an SSL certificate."

the index is the index of the certificate with irule you also have to use it. basically it is always 0, the first certificate. you can leave it empty but it will become 0 then.

what then exactly the properties are i don't know for sure, but i would say try with something like CN= and see if it works for you.