Hello Anjana,
It looks like not all necessary MQ libraries have been deployed on the PI system. Precisely speaking, can you please check if the library com.ibm.msg.client.jms.jar (that contains interface com.ibm.msg.client.jms.JmsQueueConnectionFactory) is deployed?
Class com.ibm.mq.jms.MQQueueConnectionFactory which is loaded and for which you see the error, is actually implementing the mentioned interface, but interface and class are located in different binaries: interface com.ibm.msg.client.jms.JmsQueueConnectionFactory - in com.ibm.msg.client.jms.jar, class com.ibm.mq.jms.MQQueueConnectionFactory - in com.ibm.mqjms.jar. This drives us to necessity of deploying both of these libraries on the PI system in your case.
Regards,
Vadim