Can we use QT with C# to create GUI?

.Net C# and QT are totally different frameworks but there is .Net binding for QT

My advice is do not combine frameworks they can introduce so many issues, as you said that you are a beginner you can learn Telerik UI for nice user interface

EDIT:

If you are going to combine them regardless of the suggestions not to, then at the very least, do so in places where it would make the most sense. Write a particular "layer" using one framework over another. For instance, write your GUI in QT, but write your Data and/or Business Logic layer in C#, etc... That would be about the lowest level I would go in trying to combine disparate frameworks. Gmiley is right, I did the same thing when I was working on Arduino