Can we add a point,curve,surface, part body or a parameter using KWA

Yes,

You can create simple elements through Loop (syntax is awful and usability terrible, but yes...) If you have PKT add on, then you can instanciate elements from powercopy through another powercopy or other KW actions and also through VB.

Through some tricks certain basic elements can be created through reaction and rule. At least point, curve, parameter and surface. Not sure about Partbody. Typical and very easy thing is that by creating a Curve type parameter, you can make any existing curve to become that parameter. This allows to have ready made possible options inside part and then to select which one is used on next step, this can be very similar as creation of elements.

If you have a specific problem to solve, we love challenges and might be able to help.

Can we create the point,line,curve and surface type of parameters using the "Setattribute" from rule/reaction of KWA without using the loop.?

SetAttribute can be used to add Parameters to a part and also as private children of features.

If you want to create geometry in KWA the most powerful way is using the Action feature to instantiate power copies - you can pretty much build anything this way. And you can execute Actions from Reactions.

If you have PKT you can use Knowledge Pattern to do more.