Can anyone help me how to change the servlet version in NETBEANS IDE?
I'm not sure what the question means. Do you mean you want to change the web-app version? If yes, then it has nothing to do with the IDE. It can be set in the web.xml's xsd declaration.
Note that this isn't "NETBEANS IDE" related. NetBeans is just the development environment. What's important is the project itself. When the project goes into production, NetBeans won't be there.
Customer surveys are for companies who didn't pay proper attention to begin with.