No. You need to have all 3 nameservers (at the very least 2 but 3 is better).
Your nameserver settings look good (well what whois returns to me). Your problem is somewhere else. Probably you have not set up your server correctly via de dreamhost panel.
If I ping your domain it points to: cache.bcrtfl01.us.nameservers.net.
Here's the output of "dig beinstitute.cl", it shows your webserver to be at 220.127.116.11, which is the url above (cache.bcrtfl01.us.nameservers.net).
When you set up a website for your domain on Dreamhost, it should automatically update the A entry for beinstitute.cl to point to the dreamhost webserver that hosts your site.
Really from the looks of it your problem is not related to nameservers, you've just not set up a website properly via Dreamhost.