Please check the code for ineqality conditions. is it correct ? I'm not sure about the greater than and less than sign difference.
function [c,ceq] = nlcon_reg(x)
g = 9.8;
R = 0.15;
c1 = (-g*x(1)/(pi*R.^2)) + 0.001; % quality greater than 1.
c2 = (g*x(1)/(pi*R.^2)) - 0.03;
c3 = (-x(2)/2*R) + 0.75 ;
c4 = (x(2)/2*R) - 1.35 ;
c5 = -x(3)/x(2)+ 0.01 ;
c6 = x(3)/x(2)- 0.1 ;
c = [c1,c2,c3,c4,c5,c6];
ceq = []; % total time condition.