ZD1100 will support R300 from 9.7 firmware. You're running 9.6.
Upgrading to 9.7 needs planning/thinking, read release notes, make config backup. Think about best time as it might take 60mins to get your network backup as all the APs will upgrade once the ZD has upgraded.
Note: If you go beyond 9.10 you will find that many legacy APs are not supported. Read those release notes. Don't just download and upgrade expecting everything to work because it might not!