BRING 1-1/2 cups of the juice to boil in small saucepan. Stir into gelatin in large bowl at least 2 minutes until completely dissolved. Stir in remaining 1-1/2 cups juice and milk. Pour into 13x9-inch pan. Freeze 1-1/2 hours or until frozen 1 inch from edges. Spoon mixture into food processor container; cover. Process until smooth. Pour into bowl; cover.
FREEZE 3 hours or until firm. Spoon or scoop into dessert dishes. Store leftover sorbet in freezer.