FOSUserBundle: How to best integrate login and register form in one template?
You could use (as @Sidali Hallak said)
{% render url('fos_user_registration_register') %}{% render url('fos_user_security_login') %}But use your own versions of the FOSUserBundle:Registration:register.html.twig and FOSUserBundle:Security:login.html.twig templates that don't extend FOSUserBundle::layout.html.twig
To be compliant with newer Symfony versions, you should avoid using {% render %} tag and use {{ render(controller('MyBundle:ControllerClass:action')) }} instead:
{{ render(controller('FOSUserBundle:Security:login')) }} {{ render(controller('FOSUserBundle:Registration:register')) }}
use :
{% render url('fos_user_security_login') %}{% render url('fos_user_Registration_register') %}