First try and find the project’s official subreddit or Reddit. Many times the url will be Reddit.com/r/EXAMPLECOIN – but you may need to use the Reddit search to find it.
Does the subreddit have a healthy amount of subscribers? Is the discussion objective?
Feel free to post a new question on the subreddit and gauge the responses.
Aside from the official subreddit, you will want to just do a blanket search on Reddit for the coin. See what the most active posts are discussing the project on other subreddits.
Ideally the project will have lengthy, objective discussion where you can weigh the pros and cons of the project.