is ti allow to invoke same instance of OMMConsumer.RegisterClient but with different eventqueue ? Is there a 1-to-1 mapping of OMMConsumer to eventqueue?
No, there is no one-one mapping between OMMConsumer and event queue. A different queue can be used when registering interest in a new item. All the queue's have to be dispatched though. You can also combine multiple queues into an Event Queue Group.