First check tomcat is installed on server. If not then install it as per below.

1) Go to whm >> cpanel >> addon modules >> tomcat
click on check box against “Install and Keep Updated”    click on save. It will install tomcat.

2) Go to whm >> service configuration >> service manager.
click on check box against tomcat under enabled column and then click on save. It will enable tomcat service.

Now you have to enabled jsp pages as per below.
Go to whm >> account functions >> install servlet  select the domain name click on install.
Now client is able to create jsp pages.