Heat a large nonstick skillet over medium heat. Cook ground beef, crumbling as it cooks, until browned, about 8 minutes. Drain liquid from pan. Add water and taco seasoning to beef.
Cook rice according to package directions. Add cooked rice to beef mixture; stir in corn. Increase heat and bring to a boil. Simmer until liquid is absorbed, about 7 minutes, stirring constantly. Remove pan from heat.
Sprinkle in the cheese and mix to incorporate. Top with green onions if desired. Serve with tortilla chips.