Want to find the max value

[Paknanarn23]

I want to find the Max value of Resistance_Ohm = {'Row 1'}, Column = {'Column 2', 'Column 4'},
Resistance_Ohm = {'Row 2'}, Column = {'Column 1', 'Column 3'},
Resistance_Ohm = {'Row 3'}, Column = {'Column 2', 'Column 4'},
Resistance_Ohm = {'Row 4'}, Column = {'Column 1', 'Column 3'},
Resistance_Ohm = {'Row 5'}, Column = {'Column 2', 'Column 4'} 

What should I do?