Pat the tilapia dry with a paper towel and place on a baking sheet. Set aside.
In a food processor, add the tortilla chips, chili powder, cumin, garlic powder and cayenne. Process until fine crumbs form. Transfer to a bowl. Stir in the olive oil, 1/2 tablespoon lime zest and 1 tablespoon lime juice.
Divide and spoon the tortilla mixture evenly among the fish filets then press down to coat the top of the filets.
Transfer the fish to the oven and bake for 10 minutes or until the fish flakes easily with a fork.
While the tilapia is baking, make the salsa.
In a large bowl, stir together the mango, tomatoes, avocado, onion, cilantro and remaining lime juice/zest. Season with salt and pepper, to taste.
Top each filet with the salsa and serve immediately.
Notes
Salsa can be made up to 24 hours in advance and stored in an airtight container in the refrigerator.