Amazon has opened pre-orders for the 7th volume of the JoJo’s Bizarre Adventure: Part 4 Diamond Is Unbreakable Manga. If you are interested, you can reserve the hardcover with the following link from the online retailer:
You can also take a look at the front cover design with the image placed just below this paragraph.
According to the product page, the JoJo’s Bizarre Adventure: Part 4 Diamond Is Unbreakable Vol. 7 will be coming out on Nov. 3, 2020, in the U.S. region. So, if you are a fan of the long running series, then you might want to check out the latest chapters.