How is that supposed to work?
You can do it on exhentai by setting pretty low bounty.
Or you can do it on any forum but I wonder about success rate.
because someone need to buy a manga to can it at first and if it is a paper version you even need scanner and quite some of editing later so not that easy to do.
I am trying to find a group that do scans/scanlations on a regular basis and sccept sugestions!(something like a pirate group).
Probably you should try ehentai forums then.
As it is sort of the biggest hentai pirate site in the world and most of stuff get uploaded there first