Hard to say. It could be on hiatus, but without concrete information, it's difficult to give a definite answer. Try following the mangaka's social media or the manga's official website for the latest.
In most cases, if you find a completely free version on an unrecognized site, it's likely pirated content. The best way to read for free legally is to check if your local library offers it as an e - book loan or if the author or publisher has made it freely available on their official channels for promotional purposes.