Recently I used the  latest version of ASR Deployment Planner (released on Jun/2020) to scope Auzre costs for a customer , however the ASR brought error trying to sync a VM with 6tb drive size 

Ever since 9.26 of ASR , a 8TB has been support

I logged a support query with Microsoft 

“So 8 TB support is not added in Deployment Planner of V2.52. PG has created a work Item for this improvement.”

So its 8tb!