I am using rabbitmq server and i have many users and many channel connection occur parallel. , Is there any limitations to simultaneously connect the channel in rabbitmq ?
First of all, RabbitMQ uses connection multiplexing - multiple channels may established through single connection. Due to protocol specification, there are can be at most 65,535 (note that 0 channel is reserved for system usage and that real max channels number are negotiated during AMQP handshake).
As to TCP connections, it depends on broker OS settings (ulimit).
In general, your broker can handle as much connections and channels as you allow it and as much as it has resources.