Did I understand/apply rel=canonical correctly?

Question

Search Engine Optimization

Hello!
The site is in asp mvc, the main page is available both on city.com and on citycom/Home/Index
Is it correct to insert into the Index.cshtml file/represented in the header section: or is it correct to insert into the home controller action:
<link rel="canonical" href="http://city.com" />

...
   public ActionResult Index()
        {
            
            return RedirectPermanent("http://city.com");
        }

...

Answer 1

For this case, IMHO, it's better to put a ban in robots.txt:
Disallow: /Home/Index
And do not fuss with either canonicals or redirects.