We have a cluster with a single HA pair running on 8.2.2p2 and planning to add two more HA pairs which are on 8.2.3 release of ontap. Is that acceptable, since both are 8.2 family of ontap? Or does the first pair need to be upgraded to 8.2.3?
Yes it's possible...however it's only recommended to run multiple versions of ONTAP within your cluster during the upgrade process. Also note that a maximum of two versions can be running within the cluster at a time. See the following KB