Services providing between clients and servers is an important issue in mobile ad hoc networks. Since services become complex and various increasingly, current group communication mechanisms like multicast or anycast do not completely support some kind of services such as NTP (Network Time Protocol) or threshold cryptography, etc. Manycast is a novel group communication paradigm in which a client communicates simultaneously with a number
equivalent servers in a group and can support these kinds of services. In this paper, we present a grid-based manycast scheme that employs manycast level calculation algorithm to predict a manycast region and uses an efficient grid broadcast method to support manycast delivery for large ad hoc networks. Simulation results show that our scheme not only reduces significantly more manycast overhead and the average number of replied servers but also keeps high manycast successful rate.