1. Place brown sugar, lime juice, red curry paste, and coconut milk in a large skillet, stirring to combine. Add fish to pan; bring to a simmer over medium-high heat. Cover, reduce heat to medium-low, and cook 9 minutes or until desired degree of doneness, turning once after 5 minutes. Place fish on a plate; sprinkle with salt and cilantro.
2. Prepare rice according to package directions.
3. Bring remaining sauce to a boil in skillet; boil 6 minutes or until reduced to 1/2 cup. Serve sauce with rice and fish.