Loft, sweep, or revolve are are tools that should make the indicated feature. If you could upload what you've made, it may be easier to suggest how to make it better.
Are you trying to duplicate what is shown in the image, or is the image what you have made?
If you've made the part in the image and want a different shape, what do you want it to look like?
Thank You very much. I tried again with sweep and fillet and could do it. Actually, I was trying to duplicate what is shown. Thanks once again!!