AIR cannot be used to replicate bewteen dissimilar hardware (e.g. DataDomain -> StoreOnce). Specifically AIR replication can only be done between like storage server types.
Remember the replication technology of the OST device is built and maintained by the OST vendor (not Veritas). So it is unlikely that a OST vendor (e.g. Dell/EMC for DataDomain) would want to support replicating to some other OST device such as a StoreOnce.
Even you may end up seeing the AIR jobs successful but this is NOT optimized duplication (where only changed data is transferred) that is supported by OST instead its a duplication job where it copies(duplicates) the entire backup image to the other site or storage device.