For Boiled Rice: Bring 4 quarts water to boil in large stockpot. Meanwhile, heat medium skillet over medium heat until hot, about 3 minutes; add rice and toast, stirring frequently, until faintly fragrant and some grains turn opaque, about 5 minutes.
Add salt to boiling water and stir in toasted rice. Return to boil and cook, uncovered, until rice is tender but not soft, 8 to 10 minutes for long-grain rice or about 15 minutes for basmati. Meanwhile, line rimmed baking sheet with foil or parchment paper. Drain rice in large fine-mesh strainer or colander; spread on prepared baking sheet. Cool while preparing salad ingredients.
For Salad: Stir together oil, garlic, orange zest and juice, vinegar, salt, and pepper in small bowl. Combine rice, olives, oranges, almonds, and oregano in large bowl; drizzle oil mixture over and toss thoroughly to combine. Let stand 20 minutes to blend flavors and serve.