Based on the search results, R63 in Roblox refers to a version of pornographic content created by some users who are attracted to Lego-like characters. It involves Roblox characters engaging in sexual activities and is not allowed on the platform. Some videos on YouTube show R63 content, which is often oversexualized and inappropriate. It is important to note that Roblox itself did not create R63 content, but rather some users created it on the platform.