Unfortunately not every data sheet is as clear as you have posted.
Almost all meters have separate measurement ranges for every power-of-10 range, with the least significant digit (1 count) a power of 10. So a 6000 count meter will have ranges of (for instance) 600.0 mV, 6.000 V, 60.00 V, and so forth. A 20,000 meter will have 200.00 mV, 2.0000 V, 20.000 V, etc. Sometimes the top-most range will be cut off. For instance, a 6000 count meter might have 600.0 mV, 6.000 V, 60.00 V, 600.0 V, and 1000 V. The 1000 V range effectively only has 1000 counts. The same is common on current ranges.
Sometimes you will see each range listed separately as in your example, but sometimes you will see things like "DC voltage: 0.1 mV to 600 V" or "DC voltage: 600.0 mV to 600.0 V" or "DC voltage to 600 V, best resolution 100 microvolt". All of those mean the same thing. If you know the number of counts, you can usually figure out the supported ranges.