If you are using Discovery for modeling, you can select the objects you want to mirror by use of Mirror function. You need to specify the mirror plane to mirror the selected objects about the specified plane.For parts that should not be mirrored, you would simply not select them when performing the mirroring operation. If you need to mirror certain parts and not others, you can do this in multiple steps, selecting only the parts you want to mirror each time.
 
Thanks
Deepak
You are navigating away from the AIS Discovery experience