Resolution:
Below are the properties of the Multiple engines and  properties to implement  Load balancing and Fault tolerance.

1.    If only the cluster name with be.engine.cluster.multiEngineOn property is set to true, the engines would  run in the load balancing mode within the cluster. With load balancing, fault tolerance is implicit i.e  When an agent fails, the load is redistributed between the other active agents. Multiple engines can have the same priority. In such a case, which one will get picked up, is unpredictable.

2.     You should have be.engine.cluster.multiEngineOn property to true when using multiple
primaries with Agent.agent_groupname.maxActive and Agent.agent-group-name.priority
for enabling fault tolerance.
for eg  With two inference engine and the engine1 has  Agent.&ltagent_group_name>.maxActive =1 and Agent.agent-group-name.priority = 100
and engine 2 has Agent.&ltagent_group_name>.maxActive =1 and Agent.agent-group-name.priority =200,
engine1 acts as a primary engine and engine2 acts as the secondary or standby engine.

3.       An inactive agent is like a hot standby. It is up, but not processing any events.

4.       Whenever an primary engine goes down, and maxactive is not zero, next
available hot standby is activated.

How to implementFault toleranceand Load balancing in BE 3.0?