if you just follow this way, you can make the XMPP chat room. and you have to configure some settings about a room.
- (void)xmppRoom:(XMPPRoom *)sender didConfigure:(XMPPIQ *)iqResult
this delegate method will be called ~ and you can set up what you want by XMPP - 045 document
XMPPRoomMemoryStorage *roomMemory = [[XMPPRoomMemoryStorage alloc]init];
roomID = [NSString stringWithFormat:@"%@@%@",_subjectOfRoom.text,szRoomName];
XMPPJID *roomJID = [XMPPJID jidWithString:roomID];
XMPPRoom *xmppRoom = [[XMPPRoom alloc]initWithRoomStorage:nil
jid:roomJID
dispatchQueue:dispatch_get_main_queue()];
[xmppRoom addDelegate:self delegateQueue:dispatch_get_main_queue()];
[xmppRoom activate:[[JSXMPP_Singletone sharedInstanc]xmppStream]];
[xmppRoom joinRoomUsingNickname:@"KIM"
history:nil
password:nil];
[xmppRoom configureRoomUsingOptions:nil];