DD storage capacity is reaching it's max capacity

Can anyone please help me in understanding the below,

In our environment we have Avamar--->DD and replication to Avamar--->DD.

Here in the replication DD,it's capacity is 80% now.Until the expansion of the storage,we got a list of clients from customer whose data can be deleted.

Now my doubt is where to delete the data on target avamar or target dd? either the deletion of data on target avamar or dd will result in same.