Facebook registration process

i cant find the full control of the Facebook registration process. where is that?

I'm not sure what you mean here. With JFBConnect, you have a few options for registration after the user has logged in with a social network account:
* Automatic registration - The user's account is created automatically and they don't fill out any information during th eprocess
* JFBConnect registration - The user goes through JFBConnect's registration flow, which can display fields from multiple 3rd party extensions (like JomSocial) for the user to fill out.
* JomSocial registration - The user goes through JomSocial's standard registration. They'll see all the standard fields that JomSocial shows with any information that can be imported from the social network they logged in with already pre-filled for them.

The registration option you choose is set in the JFBConnect -> Configuration -> General tab.

and if i am adding more fields how can i add them to the registaration via jfbconnect via facebook / instagram and so

The importing of fields from the social networks into JomSocial is controlled in the JFBConnect -> Profiles area. In there, you can set which field is imported into each available JomSocial field.

I hope that helps answer your question, but if you need more help, just let me know.

Thanks,
Alex