.com is a modern and the eventual replacement for .org at some point in the future.
At the moment, .com just mirrors what .org has and what is uploaded here. Also still in beta phase.
And .com will have it's own integrated forum at some point and not a separate one like here.
You could have registered on .org and then imported your account details to .com, but you've created two separate accounts by now, so not to worry. What's done is done.
For now, .org is the main site and this forum serves it's purpose for both sites, but mainly for .org.
The user you're looking for is here:
https://www.opensubtitles.org/en/profile/iduser-6499422
You can ask him your questions on his profile page.
And please don't use the forum (specifically this topic) to request subtitles. It'll become a mess and filled with chaos in no time.
Hope that helps.