im using piranha cms with ASP.net core MVC 6,
the page generated has the meta tag generator

I have checked the generated source and went thru all config and cant find how to do it,

How can i prevent or remove it?

You don’t need to remove the metatags call, just give it some arguments – the last boolean is for adding generator:

@WebApp.MetaTags(Model, true, true, false)

You can just remove the following call from your views/pages and render your own custom meta tags.

https://github.com/PiranhaCMS/piranha.core.templates/blob/master/src/web/mvc/Views/Cms/Page.cshtml#L7