Hello. Is there any way to Implement a Disclamier into the index page??? without it taking too much space??
Put it under the footer template?
It won't. Go to Templates and Styles >> Templates >> Footer Templates >> footer and AFTER the MyBB copyright, put <br /> tag and then your copyright.
You can also use the Board Copyright plugin but I don't recommend that, since it's just:
This forum [forum name] Is copyright