Founded in 1956 by: George Goldner, Joe Kolsky, Morris Levy & Phil Khals
Catalog sold in 1989 to consortium of Rhino (non jazz catalog for the US) and EMI (jazz catalog for the US, all catalog in the rest world) - EMI jazz part certainly managed by Blue Note
Top parent company: EMI Music Group ?
Distributed by: probably Blue Note ?
Catalog reissued by: probably Blue Note, with or without the name "Roulette" or "Roulette Jazz", and Rhino as well.
Note: Roulette is not a subsidiary, and before linking it to EMI Music Group, please investigate EMI history at the time of the deal.
Additional confusion: note that EMI has the rights on the brand Roulette, and lately Blue Note decided to revive it to reissue the historical catalog under that imprint.
The Roulette/(Royal) Roost jazz catalog is now managed by Blue Note (since circa post-1989, with recent CD reissues appearing under the "Roulette Jazz" imprint). The Roulette pop and R&B catalog is now managed by Rhino Records in North America*, and elsewhere by EMI, which owns the "Roulette" name and logos.
* Warner Music Group now has the rights to the Roulette pop/R&B catalogue in North America, while EMI has the rights in the rest of the world. EMI has the global rights to the jazz catalogue and the "Roulette" name.