To qualify for a top 5 ranking in Complete Raid Speed (not damage or healing), all trash in your run must be completed on HM4 (Mythic).
There is a 5 minute penalty to Complete Raid times if fewer than 12 Deathknight Captains are killed before Instructor Razuvious is killed. Full Rules
To learn more about how rankings work on the site, you can read the rankings guide. A rank with a dark gold background is considered "at risk", since it is using tricks that will likely be hotfixed at some point in the future. If an in-game hotfix is released, then the rank will be removed. Removed ranks have a dark red background.