Hollow truncated cone and hollow cylinder

I want to create a> hollow truncated cone and b> hollow cylinder in PARAVIEW. Need help and support. Consider me as a new user.

Welcome to the ParaView community, @Abhik_Roy_Chaudhury.

Since you are a new user, I suggest you take a look at the ParaView Getting Started Guide, which is available by clicking on the Help menu and then selecting Getting Started with ParaView. This guide is a quick 2 pages that will explain the basics of ParaView in a few minutes. It will make my answer more clear.

You can create cones and cylinders by using the ParaView Sources. To create a cone, click the Source menu and select Geometric Shapes and then Cone. Likewise, to create a cylinder, click the Source menu and select Geometric Shapes and then Cylinder. You can play with the properties in the Properties panel to adjust the size and shape. Both Cone and Cylinder have a Capping property that you can uncheck if you want to see inside the object from the end.

When you have time, you might want to go over the ParaView tutorial (Help -> ParaView Tutorial). It contains lots of instructions for doing things like this and much more.

I want to create a hollow cylinder of inner & outer radii RI and RO respectively and height H,
Let RI = 90 mm; RO = 100 m and H = 250 mm
Also I want to create a truncated cone of
Base Radius = 5 meter
Top Radius = 2.5 meter
Height = 2 meter

I seek a support from the fraternity to create these geometric entities.

Ah. I think you are trying to do something that ParaView is not really designed for. ParaView is not designed to be a CAD/modeling program to define geometry. Rather, it is intended to analyze the results created from modeling and simulation.

Creating meshes like this will work better in a modeling program like CUBIT.