OR Gate
The OR Gateway is used for splitting process flow in parallel executions, in case condition defined for the execution edge is satisfied. OR join gateway simply joins two or more tasks in a process flow. In Orchestra designer, OR fork gateway is shown with white color and OR join gateway is shown in gray color. Also, sigon is used to denote OR type of gateway. In following process model, we are using OR fork gateway to split process and then OR join gateway to merge two diverged flows in one flow:

Here, A and B will be both executed, if conditions that are set on edges are satisfied. In order to set condition, simply double-click on the edge (between OR gateway and call activity) and you will be able to configure condition.
Condition can be set by using XPath, JsonPath or Java code.