Do you mean can you have the SSRS service on Server A and the databases on Server B? Yes, you can, but bear in mind that you need to buy licences for each server. Or maybe you want to have two SSRS instances both pointing at the same database? You can't do that, but you can have the databases for both SSRS instances on the same SQL Server instance. You might, for example, name one database ReportServer2016 and the other ReportServer2017.