ESR works with any region. Like kadorna2 just said, make sure the disk is patched for use with ESR first (google ESR disk patcher) and make sure it is burned to a DVD, preferrably DVD-R. The reason it needs to be patched is so ESR recognises it as a DVD file in order to boot the executables, and also so that it meets the required file size to work with the PS2.
I also advise that you should use a low burn speed such as x2 for more accuracy as this will make it easier for your laser to read.
My PS2 - SCPH-77003 6C - PAL - Installed with Free McBoot 1.8b