Unfortunately, while we do carry some boots in a 'wide' width, nearly all of those are going to be a size 2E. Additionally, from a quick search it does not look like any of our vendors make a boot in a 6E. Merrell makes some of its tactical hiking boots in an 'extra-wide' size, however, even those are only a 3E.
In order to find a hiking boot in a 6E width you have a couple of options:
If you have a local cobbler they may be able to point you in the right direction for finding a company that makes hiking boots in that width.
Your local cobbler or shoe repair shop may be able to stretch a boot (depending on the boot and size) to make it more comfortable if the size is pretty close. You'll want to talk with them first to see if it is possible.