Can I recover iMessage after I deleted it in iCloud?

If you had messages in iCloud turned on Keep all your messages in iCloud - Apple Support and those messages were deleted, then they are permanently gone. If that feature wasn't turned on, you can restore from a backup -- Restore your iPhone, iPad, or iPod touch from a backup - Apple Support.

Once you deleted something in the cloud, it is gone forever. Unless, you have a local copy stored.