This is more of an OS requirements question. I would check this:
Master Note of Linux OS Requirements for Database Server (Doc ID 851598.1)
Requirements for Installing Oracle Database 12.1 64-bit (AMD64/EM64T) on SLES 11 (Doc ID 1519770.1)
Data Guard Support for Heterogeneous Primary and Physical Standbys in Same Data Guard Configuration (Doc ID 413484.1)
Which version of Oracle? Oracle certifications for OS platforms are version dependent.
For Oracle 11.2, you can use SLES 10 or 11. You'll also want to use the same OS as the primary.