Go through the below link -
Above document have mentioned all the paths for upgrade.
You need to upgrade R12.0.4 to R12.2.0 then you need to apply R12.2.5 or R12.2.6 on top of R12.2.0
Oracle E-Business Suite 12.2.6 Readme (Doc ID 2114016.1)
Oracle E-Business Suite 12.2.5 Readme (Doc ID 1983050.1)
Suggest you to go with latest version which is R12.2.6
You could refer the following Note helps you plan your move to Oracle E-Business Suite Release 12.2 Oracle E-Business Suite Release 12.2: Technical Planning, Getting Started, and Go-Live Checklist (Doc ID 1585857.1)