This paper exhibits the confidentiality performance study of a cooperative multicast network consisting of K asymmetric relays over Nakagami-m fading channels, where the communication links face uneven signal-to-noise ratios (SNRs). Although, conventional symmetric deployment of relays are convenient for analysis purposes but this assumption is not always effective in real cooperative network applications. So in this analysis, a cooperative multicast network is considered where a group of asymmetric relays cooperate in communication between a base station and multiple destinations under the nose of multiple eavesdroppers. Based on the given probability density function (PDF) of SNR for a point-to-point communication system, the analytical expressions of the PDF of SNRs are developed for multicast and eavesdroppers channels. Then, using these PDFs, the analytical representations for the probability of non-zero secrecy multicast capacity and the secure outage probability are derived for analyzing the performance of the proposed model. Finally, analytical results are verified with Monte-Carlo simulations. [ABSTRACT FROM AUTHOR]