Is there a such plugin that makes people have to post a comment to see the content (i.e. download links, or some info). I looked for it but i couldn't find yet.
Doesn't sound very practical. I don't think it exists. Why not just have people log in? You can't really do anything with comments. It's not like comments give you a backlink. and you will just encourage people to leave any old crap. At least if they log in, you have email addresses to build a mailing list off of. Just a suggestion.
I have a video downloading site, but i also have direct links for each videos, i don't want everyone to see that. Yes i could use hidepost plugin and make a group see only but then they can leech off all the files. So yeah, thats why i needed
Well, I don't think commenting is necessarily the gatekeeper that you are looking for. To comment, users need to be logged in, so that pretty much gets you there. I still don't under stand how you want to incorporate whether or not a reader leaves a comment, with access to the files. Can you explain how you are trying to tie the 2 together?