SQL Server (2012/2014/2016), Oracle (11g/12c), or SAP ASE (15.7/16.0)
If you need the for Crystal Reports Server 2016 (including patch-level limitations), let me know and I can extract the most current published compatibility. crystal reports server 2016 system requirements
The following hardware requirements are recommended for Crystal Reports Server 2016: SQL Server (2012/2014/2016), Oracle (11g/12c), or SAP ASE
It is important to note that Crystal Reports Server 2016 is a 64-bit application. Therefore, the underlying Operating System and database drivers must be 64-bit compliant. SQL Server (2012/2014/2016)