Can any One Guide Me How to Create a Dummy Leg Support in a Caesar Model and how can we give forces and Loads in them.

Use the forum 'search' facility, try 'dummy leg' or 'trunnion', and read the Caesar II User Guide.

If it is a pipe dummy leg, just model a piece of pipe from mid-point of bend where it is coming from, to where the support centerline is that is supporting the dummy leg. No need to model past that.

You then have the issue of what SIF to use at dummy leg to bend intersection. I use a program called FEBend to calculate SIFs. I apply the SIF at the base of the dummy leg where it attaches to the bend, and I apply a SIF to the TO node on the bend. You have to turn on the option "Allow user SIFS at Bends" in the Caesar config file.

Also, I make the bend a "two flange" bend to account for the extra stiffness of the dummy leg acting on the bend's ability to ovalize.

Now, with the SIFs in your Caesar model, your Caesar output should indicate an overstress at your bend/dummy leg, if there is one.

Sometimes if it is a critical connection and I am concerned with a high stress, I will put the loads back into FEBend and recheck stresses there.