Hi Quaritexa,

re:
> I know about single point. Rhino allows you to delete rows or columns.
> How to delete the same in moi?

MoI does not currently have a method for deleting rows or columns of surface control points. That's something that is very rarely, if ever, used. Deleting points like that will alter the shape of the surface often in strange ways if it has a non-uniform knot vector.

To repair something like your example there it's better to reconstruct it.

In general surface control point manipulation is not a focus area for MoI, because of the NURBS surface row/column organization of surfaces. If you want to work on something by modifying surface control points you are better off doing that in a sub-d modeling program.

- Michael