Yes, we do. You can connect to an IPv6-enabled server by using irc.darenet.org, which contains both A and AAAA records.
You will be able to hold up to 5 connections per /48 subnet, which is the normal subnet mask your ISP should have assigned you. If that is not the case, and your ISP has assigned you a different subnet mask, please contact us stating this problem, be sure to include your IP address, subnet mask and the ISP. We may make an exception for this specific ISP.