Implemented Community Builder extension on client's website tnssecurities.in. While Login form showing, Register button not showing. Tried to post this problem on their forum but came to know forum membership not free.
I think the problem is your module doesn't have registration button coding or check your backend -> Extension manager -> Module manager -> Select your module and check if any options are available for show registration button in your site.
You need to use the Community Builder Login module. In this module there are several tabs. In the tab Login Options, you need the setting Register Login Link. When it is set to Hide you will not see a link to register: set it to one of the other 3 values (Text, Icon, or Icon and text).
The forum is free, you need to register first, and some parts of the forum are read only when you do not have a paid subscription.