Hi, on R12.1.3
According to note 437878.1 , I have to apply the patch 14825718.
On which tier should it be applied? DB, Forms, Concurrent?
It is a Forms patch. Please use the step by step notes from the note you are looking at to apply.
Upgrading OracleAS 10g Forms and Reports in Oracle E-Business Suite Release 12 (Doc ID 437878.1)
If your concurrent manager tier is separate from your Forms tier, you need to apply these patches there as well.