How to determine the packing geometry of compounds with contradicting coordination number and radius-ratio values?
You've calculated your radius ratio value and you know you're between 0.414 and 0.732, so cubic is off the table, based on your chart.

You're looking at either square planar or octahedral. Your chart also says that ionic compounds do not use square planar packing and the coordination number would have to be 4. LiBr is an ionic compound (like NaCl) with a coordination number of 6, therefore you're looking at octahedral.

From there you can determine your "specific" answer.