how to link the Radio Box with Picture Box

If it's a Winform application, then you could do something like:

Add an ImageList control and set its "Images" property to your collection of images.
 
Then on radioButton_CheckedChanged event handler set your pictureBox image to ImageList collection accordingly.

Code would be like this:

       private void radioButton_US_CheckedChanged(object sender, EventArgs e)
        {
            pictureBox1.Image = imageList1.Images[0];
        }

        private void radioButton_IN_CheckedChanged(object sender, EventArgs e)
        {
            pictureBox1.Image = imageList1.Images[1];
        }

Let me know, if it's not clear to you.