At this point it seems to make little sense to register new accounts on Reddit. The registration is de facto closed. You can register, but you would not be able to do anything with a new account on most parts of Reddit without enough "karma" points. If you try to post a message, even on small subreddits, it would most likely be instantly deleted by a lazy moderator's bot. You would not even be able to send private messages, post to your own profile or create a new subreddit.
The required number of points may vary depending on the subreddit and is not disclosed. Although there is an unofficial list of subreddits which allow newcomers to post. Apparently, after registering, your only choice is to go there and write about something you don't give a damn about, just to earn enough points and be allowed to discuss things that really interest you on other subreddits... only to be banned there for some petty reason and have to start everything over again. Which honestly sounds like a Sisyphean task.
To put it shortly, most Reddit moderators make it clear that new members and new ideas are not welcome in their communities. Is it really worth it to try so hard to get on their website, which is already turning into a graveyard of deleted comments and profiles, patrolled by bots that are tasked to "shoot" any karmaless "vagabonds" on sight?