Fix Central often delivers individual *.tar or *.bff files, not ISO. To create an update ISO: gather updates in a directory, run mkisofs -R -o aix61_update.iso /update_dir , then burn.
Some IBM Business Partners maintain legal archives of older media. Contact your regional IBM reseller; they may provide ISOs for a nominal fee if you have license proof. aix 61 cd iso download upd
If you are searching for this, you likely fall into one of two categories. Here is the reality for both: Fix Central often delivers individual *
Note that standard support for AIX 6.1 TL9 ended in 2017, and extended service periods typically concluded around April 2022 . run mkisofs -R -o aix61_update.iso /update_dir