Some comments on the support systems documentation. You will find the supported systems document in the products
https://4js.com/en/download/products and downloads section of the website
https://4js.com/en/download/documentation. It should be the 1st entry in the list and the current version as Seb gave you is
https://4js.com/mirror/documentation.php?s=genero&f=fjs-genero-2.50.XX-PlatformsDb.pdf.
Recent versions of this document include the database clients we connect to. Note this is not the database version, but the database client, so you won't see Informix 11 in the list, you see an entry such as "Informix CSDK ESQL/C 3.50 & 3.70 & 4.10". We connect to the database client, not to the database.
For older versions of our product, in the bottom right corner of the product and documentation download pages, there is an entry "Archived Release". This is where you will find downloads and documentation for older versions of our product, and in there you will find an entry for the supported systems document. This is what Seb also linked you, the links are not permanent, note the random letters in Sebs URL. Being an older document, the format and content isn't as good as the recent examples, and sometimes it pays too look in more recent versions to find the info you need.
The key thing I'm going to point out from those links is that Genero 1.3 is not supported on AIX 6.1, so you should not even be considering running it on AIX 6.1. Whilst we could run tests to see if it passes QA, the reality is that if we did find an issue, chances are it has been fixed in a more recent version, and it would be suggested that you upgrade. Even if it was a new issue, it would be unlikely we would apply a patch that far back. Generally patches are applied to current (2.5) and previous version(2.4).
You have indicated that you are upgrading server and database versions, so presumably there is a level of QA testing going on at your end to make sure your programs still run, so I would strongly recommend you take the opportunity to also upgrade to a current Genero version. As well as being able to run on contemporary O/S and databases, you will also be able to take advantage of new functionality and the approximately 10 years of investment in the product since the days of 1.3
Reuben