If i go by XEP-0077: In-Band Registration i doubt that the server will make me unregister, I don’t want to leave xmpp server i just wanted to leave only specific room which someone might have added me and i don’t wanted to be part of discussion anymore.
If you send this to the JID of the room, then it should only unregister you from that room (not the entire server. It is basically the reverse operation of what is described in section 7.10 of XEP-0045: Multi-User Chat