Mobile Ad hoc Networks (MANETs) are a subclass of remote network system having exceptional characteristics of dynamic system topology and moving nodes. The utilization of remote advances is expanding and it impacts in the improvement of new hypotheses and structures for the interchanges. One of these new advancements is the portable systems. The routing is a fundamental part in the achievement of the secure communication in these structures. Routing method is the basic and essential execution factor in the Mobile Ad-hoc Network. The routing methods in MANET are practiced to deal with much number of nodes with limited resources. There is an assortment of routing method exist in MANET. Because of the dynamic topology and non-framework, network members collaborate with their neighbors to route the data packets. Cryptographic methodologies have been familiar with secure gathering for example, Private and Public Key Infrastructure. The self-governing and circulated nature of MANETs requests a decentralized validation administration, where Public Key Infrastructure is viewed as a superior arrangement. Key administration in the MANET is a critical issue concerning the security of the network communication. By setting up key administration technique, arrangement can be given to administrations like confirmation, information respectability and information classification. Secure routing and information transmission have an important role in Ad Hoc system as it is increasingly defenseless against numerous attacks because of its auxiliary qualities. In this paper, a survey is done on different routing methods, secure communication process and methods to improve the unwavering quality of information transmission.