The word 'registered' can mean a lot of things. In your case, it means that you have signed up to that network's nickname services bot (NickServ), validated your email address, and identified or logged into that network via bot commands or connection auth.
If you need assistance with this matter, you must join that networks's support channel. You can find it by typing /join #networkname or /join #help or /join #irchelp
This web forum does not condone, nor will assist you with methodologies related to, the piracy of intellectual property such as eBooks. Please do not ask, nor tell us your motivations.