In our current project we have a requirement to use customers InHouse Forms. Is

You can attach HTML, JSP, or PDF forms to a node, however note that these forms are only supported in the Portal interface -

forum.appian.com/.../Designing_and_Managing_Forms.html

This documentation link shows an example that uses HTML forms (Note that this feature is deprecated) - forum.appian.com/.../HTML_Forms.html

Appian allows for HTML, JSP or PDF forms to be created. But please be advised that this is not supported on mobile devices.
We recommend that you consider rearchitecting the solution using the supported Tempo or SAIL form functionality.

I was searching some information for Custom Forms like HTML or JSP then I got this thread. Abhi mentioned that these forms work only on portal interface, does that mean I can add these forms on UI Task. If somebody used in latest version then more helpful. We are not using this for for mobile device.