You can combine the autofs OSREL variable with the CPU variable to form a name that determines both CPU type and OS release.
bin aa:/export/local/bin/$CPU$OSREL
For clients that are running Version 5.6 of the operating system, export the following file systems:
For SPARC clients – Export /export/local/bin/sparc5.6.
For x86 clients – Place executables in /export/local/bin/i3865.6.