How to add Jtab modules

In your joomla backend install the module mod_jtabs.zip. Go in extensions - modules and for jtab module chose position "tabs".

In Module Parameters put in "New Position" any module position you want to show there (example right or tab).
All modules which are on the position you will chose for "New Position"  (example left or tab) will show there depend on which menu those modules are published. If you use for example module right then the modules will show in both right position and jtabs position. That is why the module "tab" is created and does not exist visually in template.
So "tab" module is used only to add modules which you want to show in tabs and that they are not visible in any module.