I recently wanted to change the nameservers for my .info domain registered at domainsite. However, I kept on having a nameserver invalid error and had to send a support notice to domainsite. This was their reply:
The problem is due to the fact that your desired name servers have extensions (e.g. ns1.yournameserver.COM and ns2.yournameserver.COM) different than those of your domain name (e.g. yourdomainname.ORG). .COM domain names, for instance, do not “naturally” recognize .ORG name servers; likewise, .ORG names do not “naturally” recognize .COM (or .NET, .INFO, etc.) servers. While you cannot make such nameserver combinations work, as you know, we can. Thus, I have “introduced” your specific server set to the registry software in charge of your name registration. You should be able to make them authoritative for your domain names at this time.
I thought that this sort of "problem" only plagued .info domains registered at domainsite but I never knew that there would be a "problem" when changing nameserver of different extensions. It's weird as I only found out about this only now when I have successfully changed nameservers of various domains. Can someone enlighten me?
I have never heard of a problem setting nameservers between TLDs with any other registrars. As long as the nameservers are registered with the registry, you should have no problem setting the nameservers regardless of the tld.