I want to know whether 2010年10-12 indicates a range or an specific date.
In that case it would be saying 10th month through 12th month
See @Ming's comment about the specific date format.
There could be a case where the writer is using their own unique format, but that would depend on context
In most cases, it means 9/2010-12/2010, unless in specific text it has some other meanings.