Please follow the document: Oracle E-Business Suite Release 12.2.6 Readme (Doc ID 2114016.1)
You can download directly from Patches and Updates (MOS) - Patch 21900901
I believe you can download from E-Delivery also but I recommend going for given Document ID and follow the steps.
I would always recommend you to go for the latest version which 12.2.6 as of now.
We are working on R12.2.5 supports/upgrades for may clients and its good and stable version
Currently working on R12.2.6 upgrade from R12.1, will see the result
Thanks Shaik and ALL
Can you please share me the procedure how to upgrade 12.1 to 12.2.6?
What you saw "somewhere" is just like the virtual appliances you download from edelivery but it is available only on Oracle Cloud (marketplace).
Oracle does not release trial EBS products. If you see something is released then it is for production use.
The only exception is the early adopter program, which is a special case and you do not need to worry about it.
Follow the upgradeguide E48839-14 to achieve R12.2 upgrade from 12.1
Oracle® E-Business Suite Upgrade Guide Release 12.0 and 12.1 to 12.2 Part No. E48839-14
Below are R12.2.5 and R12.2.6 Patchset Read me doc id's
Oracle E-Business Suite 12.2.5 Readme (Doc ID 1983050.1)
Oracle E-Business Suite 12.2.6 Readme (Doc ID 2114016.1)