There are two approaches you could use. One is just to specify the width of each field:
fprintf(fid{i},'%12s\t%12s\t%9.6f\n', ...)
Another is to convert your cell arrays into arrays of strings so each country name is padded with blanks until they are the same length:
country1 = char(R_Value{:,1});
country2 = char(R_Value{:,2});
....
fprintf(fid,'%s\t%s\t%9.6f\n',country1(j,:),country2(j,:),R_Value{j,3});
Either way, you need to provide extra formatting info for the numbers to get them lined up.