Hi, I want to have a topic without need to be sign in to read it, but I would like keep it a private content, how can I configure that topic or page can not to be indexed by google and the Search engine of IPS?

You can manually add a noindex Meta Tag to the page: https://invisioncommunity.com/4guides/promotion/seo-r295/#metatags

 

SEO Essentials by @Daniel F offers an option to disable indexing.

Here you are - https://forum.invisionize.pl/files/file/918-dp45-disable-indexing/