Sorry Kerman, seems like I've beaten the records you posted earlier. Not sure if it's the largest found since the last update of the record book, but it's by far the largest as of the last update to it, beating a whopping 3 records.
CMDR: Draco25240
Ship: PFS Asylum Express
Ship type: Imperial Eagle
Discovery info: Discovered by CMDR Draco25240 on one of the last days of his 8 months long journey to cross the galaxy in his Imperial Eagle, this behemoth of a ring was found around a T-type brown dwarf, orbiting a massive F-type hypergiant star. Although hardly visible due to the low density of asteroids in the ring, this ring stretches out to an impressive 0.15 AU out from the parent "star", making it easy to fly into it at high speed by accident if you're not careful. Approach with caution.
Single ring with the largest outer radius:
Dryao Aowsy LM-W e1-1469 5 A ring, with an outer radius of 22,625,258 km (2.42x as large the one in the record book)
Heaviest single ring:
Dryao Aowsy LM-W e1-1469 5 A ring, with a mass of 29,851,444,576,256.0 MT (3.36x as massive the one in the record book)
Widest single ring:
Dryao Aowsy LM-W e1-1469 5 A ring, with a width of 16,976,443 km (1.93x as wide as the one in the record book)
System map screenshot: