How to set JVM arguments in WebLogic 12c

Steps to set Custom arguments to set in Weblogic JVM

In the Domain Structure pane, expand the Servers node.
Click the name of the server that you want to configure.
In the right pane, click Server Start.
Select Lock & Edit.
In the Arguments text box, provide the JVM options. After inserting your options, click Save.
Restart the server so that the new settings are used.