If you want to attach NURBs surfaces, understand that both the surfaces should have the same amount of U's and V's going in the correct direction (or have the same ratio of U's and V's) Use rebuild nurb surfaces to correct that under "Edit Nurbs" for each of the surface.
You can also attach NURBs surfaces by using the stitch tool. This tool doesn't require that you have the same UVs going in the correction direction of both surfaces, but it may be wise to do so, just as if you were going to attatch them using "attach surfaces" under 'Edit Nurbs"
To use the stitch tool, > Edit Nurbs > stitch > there are 3 options to choose >
if you are just stictch one edge to another, use "stich edge tool"
If stitching more than one surface, use "global stitch"
after stitching the surfaces, move one surface and see what happens.
mess around with them to understand them better.
(Note: if you delete thir history after stiching, they become sepearated sufaces again, try deleting their history and then moving them to see what happens)
not sure if this is what you wanted though...
9 months into Maya...and still learning...
0 experience with any other 3D programs