Using CF11 with IIS 10 is not possible by wsconfig tool. any idea how to make it work otherwise or is it not possible at all?

Not helpful I know, but you really shouldn't be running CF11 now, too many security fixes since then.

You might be able to reverse proxy via ports…thought it may only work for one domain per CF instance.

Follow the manual steps to configure the connector. https://helpx.adobe.com/coldfusion/kb/coldfusion-iis-manual-connector-configuration.html

Please do not use ColdFusion 11 in a publicly accessible production environment. It has multiple known unpatched CVEs and will be hacked. You are inviting bad actors into your server space (or that of your client).

@adwwad afadawdwa unless you are rendering cfreports or using some of the Adobe Specific tags, you might want to consider using Lucee to run the site. Depending on your budget, your other option would be to look at a fully managed CF host to move the site to so you can ensure the latest version of either Lucee or Adobe CF is used.

It's probably not possible, as IIS 10 may be too new in this case. The supported versions of IIS for ColdFusion 11 range from 6 to 8.5. That said, you should heed all the advice you've received about ColdFusion 11 being outdated

Thanks for the answers, I know it's outdated, we are updating.