Registro.br has a (non-standard) requirement that we configure the domain first, when we normally require the registrar do it first. Because of this, we don't properly support them. You must change your main domain to your registro.br domain, then wait for it to set up (usually a few hours is sufficient to get Registro to see it), then change your NS records at Registro, then change your main domain back to something else, then add the registro.br domain you bought as a parked domain, and wait 48 hours. The proper solution though, is to transfer your domain to a normal registrar. Registro.br is one of only two we know of that has this odd requirement (the other was some tiny company in India if I remember right).