Program to drow graphical circle in c?

Standard C does not include any graphical functions thus there is no standard method for drawing circles. For that you will need a graphics library suited to your specific hardware and operating system. Specific methods will vary according to which library you use, however there are also generic library's available depending on your hardware's capabilities. Consult your library's documentation; there will typically be simple examples to demonstrate the library's core features, including drawing circles.