Cut the fresh coconut into small pieces to make them grind properly and smoothly. Deseed the grapes if they seeds. In a mixer grinder grind the coconut separately to a fine paste. In another big grinder add the grapes, lime juice and sugar and grind. Then add the coconut paste to it along with coconut water and grind smoothly. Your tropical drink is ready. Pour it into your serving glasses. Top and garnish it with some chopped Grapes and serve.