Hi,
JA Teline II is Joomla 1.5 and we no longer can support 1.5 versions of Joomla. You should consider migrating to Joomla 2.5 / 3.x and use latest Teline series of templates.
The registration process is handled by joomla core and template has no role to play in that workflow.
Yes, if this is the source >> http://easycaptures.com/fs/uploaded/815/7895841555.jpg , the JA login module, then you can disable it and use direct login links with antispam (recpatcha). AS Joomla 1.5 is no longer supported, it would be hard to find login extensions to help in your case.
For now, I am not sure how to help you out.
Regards