Chop chicken breast in small pieces. Combine chicken, chicken broth, tomato sauce and taco seasoning in a large saucepan; bring to a boil; simmer covered 5 minutes. Add corn, black beans and rice. Cover and remove from heat. Let stand 5 minutes. Fluff and serve on crunchy tortilla chips. Top with cheese, sour cream, shredded lettuce, and avocado.