Yes it is a cross platform migration.
You may use a method like XTTS for database tier migration, and you will install the techstack from scratch and copy the all other things and compile on target for application tier migration.
It is a complex migration and in my blog, you may find some examples of it.
for instance:
https://ermanarslan.blogspot.com/2015/02/exadata-ebs-11i-exadata-migration-from.html Why 11i apps tier is not certified and not supported in 64 bit Linux systems?
The answer is it is just not certified :) It is not optimized to run on 64 bit Linux Systems.
On the other hand; the difference between R12 apps tier and 11i apps tier is; EBS R12 apps tier, which also has 32 bit executables and components, is optimized to run on 64 bit Linux systems.
Linux 6 is not certified with Oracle EBS 11i in the first place. So, you are on your own.. It may still work (I m waying this both for linux 6 and 64 bit arch..), but you may need to do extra stuff, some customized compilation and support your system by yourself. So I don't recommend to go that way.