Application for wireless sensor network is notably different in its characteristics and requirement from a standard WLAN. When a critical event triggers a surge of data generated by the sensor, congestion may occur as data packet converge toward a sink, which causes energy waste, throughput reduction, information loss, hidden terminal problem and link failure in contention based MAC protocol. Due to hidden terminal problem the RC-MAC and CSMA/CA protocol sensing is used to reduce the channel contention and radio collision. The formation of a new tree for avoiding link failure-a MAODV routing protocol was introduced in this paper and the performance of this protocol is measured using the above parameters. The demonstration of a near optimal throughput at each sensor and to achieve congestion avoidance in presence of a multicast routing towards a multiple sink is also done.