lita-broadcast is a handler for Lita that allows messages to be sent to multiple channels simultaneously.
Add lita-broadcast to your Lita instance's Gemfile:
gem "lita-broadcast"
The command tell #room1 #room2: <your message here>
will send everything to the right of the :
to #room1 and #room2.
For example,
<john> lita: tell #engineering #operations #helpdesk: hello
The channels #engineering #operations and #helpdesk will all see the message:
<lita> @john says: hello