Whisk together all marinade ingredients but the tilapia. Add the tilapia and flip around to coat. Transfer to a plastic bag and seal, removing excess air. Let marinate for 1 hour.
Meanwhile, prepare the mango salsa by combining the mango, red onion, cilantro, and jalapeño to a mixing bowl. Toss to evenly combine. Add lime and lemon juice and toss. Refridgerate until ready to serve. Can be made a day ahead of time.
Once the tilapia is ready, heat a nonstick skillet over medium-high heat with about 2 tbs oil. Remove tilapia from marinade and let excess drip off. Cook the fish about 3 minutes per side, or until the fish is cooked through and easily flakes.
Warm tortillas per package directions. Cut tilapia filets in half lengthwise or into chunks. Build the tacos with the warmed tortillas, cooked tilapia, and mango salsa. Top with cotija cheese and enjoy!