Prepare grill to high heat.
Pat scallops dry with a paper towel. Sprinkle 1 1/2 teaspoons fish rub evenly over scallops. Coat scallops with cooking spray. Place scallops on grill rack; grill 3 minutes on each side or until done. Remove scallops. Add pineapple to grill rack; grill 2 minutes on each side. Remove pineapple from grill; chop pineapple.
Combine salad greens, lettuce, pineapple, and avocado in a large bowl.
Chop large pieces of chutney. Combine chutney, lime juice, olive oil, and remaining 1/2 teaspoon fish rub in a small bowl. Add dressing to salad, and toss well. Place 1 1/2 cups salad into each of 4 bowls. Arrange 3 scallops over each salad.