Heat oven to 350 degrees. Spray a 2 quart casserole with cooking spray. In casserole, stir chicken, rice, tomatoes, soup, corn, taco seasoning, and 1 cup cheese until well mixed. Cover and bake for about 1 hour or until rice is tender and mixture is heated through. Top with tortilla chips; sprinkle with remaining 1/4 cup cheese. Bake about 10 minutes longer or until filling is bubbly and cheese is melted.