FX-6300 can run 1866MHz with one DIMM per channel and 1600MHz with two DIMMs per channel. The motherboard is a dual channel motherboard.
The motherboard doesn't have XMP settings for memory. I couldn't tell you what using OVERCLOCK Mode does.
You would probably need to set these manually or the memory would run at more conservative SPD (Serial Presence Detect) settings.
DRAM Timing Configuration
You would set the DRAM Frequency to DDR3-1600MHz or X8.00.
The Dram Timing are 9-9-9-24. The DRAM Timing Control needs to be set to [Manual]. Set the first four number beginning with Cas Latency.
Using more than one stick of CMZ4GX3M1A1600C9 is not guaranteed to work so all bets are off if you are using multiple modules.