You can't really. Most channels are +i because they don't want anyone to join it except specific users that they already know. Think of it as a private party, guests have already been pre-determined, and only they will be allowed in.
There's little you can do to contact the ops of the channel, although a few methods could be used I guess.
If the network you use has ChanServ, or some other channel service (such as 'X', 'Q' or 'L') then you could use certain commands with them that gain information about the channel - one of those bits of information is always the 'Founder' of the channel (the person who owns and manages it). You could contact them when they are online (use
/notify nickname) and ask for permission - remember, the chances of permission being granted is small. You will need to ask in the #Help channel of the network what the command is to gain info about the channel. With ChanServ it is often [/b]/chanserv info #channel[/b] and with the other services, it might be something like
/msg X info #channel.
You could also try
/mode #channel b - this will return the channel ban list, and along with it, the nicknames of the ops who set the bans. You could again use /notify to know when one of these ops is online and ask them for permission. The bans look like this:
#channel *!*@some.address.here set by
OpNick!OpUser@ops.hostname.here (Day Month Date Time)
The bit in red is the nickname of the op that you need to put on notify and ask for an /invite into the channel. It will not be in red when you use it in mIRC, I just used that to make it clearer! If there are no bans set you will simply get the message '#channel End of Channel Ban List' or words to that effect.
Best of luck
Regards,
