The projection of a line on axes are 6,2,3. What will the direction cosines of the lines be?

6^2 + 2^2 + 3^2 = 49

so the direction cosines are
(6/7 , 2/7, 3/7)

notice that (6/7)^2 + (2/7)^2 + (3/7)^2 = 1