It is above the EPA action level of 4 pCi/L, and it is not an emergency. For a home not being sold, Ohio's testing strategy calls for a second short-term or a long-term test at that level, then a fix if the average stays at 4 or more.
More detail
On the EPA's lifetime risk table, 6.5 sits between the 4 and 8 pCi/L rows, where about 7 to 15 of every 1,000 never smokers, and about 62 to 120 of every 1,000 smokers, could get lung cancer from a lifetime of exposure. That is why the answer is to fix it this season, not to move out. If the number came from a real estate test, Ohio's strategy is simpler: 4.0 or higher means fix the home, without a second test. Check how the result was produced before acting on it. The report should show start and stop times, the device and its serial number, the tester's Ohio license number, and where the device sat. A kit left in a laundry room or beside the sump does not meet Ohio's placement rules. See how to read an Ohio radon report.