Hi Mala, maybe another possible method would be to make a version of what you want along a straight line so it's a cylinder and then bend that into a circle using Transform > Deform > Flow.

That would produce a slightly different result than the tapered extrusion one above, because when you cut the toroidal shape with a planar cut, that produces some asymmetry with that cut being planar but the other side where the tapered extrusion intersects the inner tube will not be planar. With a Flow method you would have both planar cuts in the base shape and they would both deform when the shape bends into a circle using Flow.

You would use curve to curve flow for that with a line down the center of your cylinder as the base curve and a circle as the target curve.

- Michael