HEAT oven to 400ºF. Microwave soup, water and VELVEETA in microwaveable bowl on HIGH 3 min. or until VELVEETA is melted and mixture is well blended, stirring after 2 min.; pour 1/3 into 13x9-inch baking dish. Set aside. Add broccoli to remaining soup mixture.
STUFF manicotti with chicken; place in baking dish. Top with remaining soup mixture and Parmesan; cover with foil.
BAKE 45 to 50 min. or until manicotti is tender and chicken is done.