I need to make validations according to the list settings.
I think you can make it using a REST call to >>> url: "http://<site url>/_api/web/lists(guid'da58632f-faf0-4a78-8219-99c307747741')
Here is the Fields REST API reference
Currently Nintex forms is not getting that info.
I'm not sure I quite understand what you are trying to do.
What are you looking to do with this information? ie: use it for validation? display it on the form?
Retrieving data ...