I found the solution, It may be helpful for someone.
Thank you
a=([char(949) '_{2}']);
b=([char(949) '_{3}']);
c=([char(949) '_{1}']);
d=([char(949) '_{r}']);
e=([char(949) '_{\theta}']);
legend(a+" = "+d,b+" = "+e)
t.FontSize = 10;
s.FontAngle = 'italic';
xlabel ([char(949) '_{1}']+"(%)")
ylabel ([char(949) '_{2}']+ " , " +[char(949) '_{3}'] + " (%)")
ylim ([0 .16]);
xlim ([0 .16]);
txt1 = (" \leftarrow"+ a+ "=" +b +"=" +B + c);


