It used to be simple to find the supported browsers against Oracle Forms. For convenience, perhaps only for me.. ) hereby the links.

To be found through the link of the Oracle Fusion Middleware Supported System Configurations:

https://www.oracle.com/technetwork/middleware/ias/downloads/fusion-certification-100350.html

Oracle Software Web Browser Support Policy:

https://www.oracle.com/technetwork/indexes/products/browser-policy-2859268.html?SSContributor=true&SSHideContributorUI=true