That means 6 and half characters? How can you have half a character?
If that means 6 characters before the decimal point and 5 after the decimal point, dream on. There is no way you are reading the accuracy of a resistor to 0.00001 ohms, no matter how you try. Perhaps you ought to observe the tolerance of the resistors you are trying measure.
Well if he is talking digits like digital multimeters rate them:
6.5 digits means a display capablity of from 0000000 to 4999999 with the decimal point set anywhere among those digits depending on the ranges and units the DMM has avalible, and leading zeros blanked of course. Upon reading a value higher then the maximum display 'count' possible, the autoranging function would switch to the next higher units range if possible or change to a 'overflow' indication.
A full 7 digit display would of course span 0000000 to 9999999
Lefty