Combine taco seasoning, lime juice and oil in small bowl; mix well. Brush seasoning mixture onto chicken breasts.
When ready to grill, place chicken on gas grill over low heat or on charcoal grill 4 to 6 inches from medium coals. Cook 15 to 18 minutes or until chicken is no longer pink, turning once. Or broil 4 to 6 inches from heat 12 to 15 minutes, turning once.
Slice chicken into strips, spoon into shells, top as desired.