|Generally-speaking, DVD-5 is your "regular" single-layer dvd blank media (4.7Gb), and DVD-9 is dual-layer (dbl-capacity). Only compatible burners can burn dual-layer, independently of burning software.|
What the OP may be asking about is burning a dual-layer movie DVD to a single-layer blank. Although this may sound like trying to pour a quart of liquid into a pint jar, that is a simplistic view. DVDShrink (which happens to use the Nero burn engine) can sometimes accomplish this under certain circumstances. This is just a wild guess, of course.
Since we did not get much pertinent information from the OP, there is little detailed advice we can offer. Why is it so difficult for people requesting help to at least put some effort in posing their question/problem?