I want to make a proper rotation matrix but the normals are not perpendicular to the other vector attributes. I was hoping as to what I'm doing wrong ?

Are you trying to build the matrix from the normal and two basis vectors, which are not orthogonal?

You can try making orthogonal basis vectors with makebasis(), using the normal for the z-axis, and one of your other vectors that is not coaxial to the normal as the up-vector.

http://www.sidefx.com/docs/houdini/vex/functions/makebasis [www.sidefx.com]

Then it's just a matter of building the matrix from vectors, which you can do with the set() function or the vector to matrix3 vop.

Are you trying to build the matrix from the normal and two basis vectors, which are not orthogonal?

Yes, what am I doing wrong; without makebasis() ?