How do you expect anyone to have the remotest idea about a subreddit recommendation if we have no clue what your blog is about?
You need to search for relevant topics that fit your blog. You will surely find it, but you will know what will the best.
I am looking for subreddits where public is allowed to post. Searching will give results of subreddits which are highly moderated?
For that, you need to find a subreddit for yourself, because all subreddit has their personal rules and regulation, so before posting links to that subreddit, you need to read the rules for posting in that subreddit, otherwise you may be got suspended.
The most important factor from Reddit is the massive traffic you can get. Recently outsourced some Reddit posting and got great traffic/links, traffic was up several hundred percent during that time. You can also get some good results from Quora.