Corner radius for all 4 edges:

http://i.stack.imgur.com/O8qTg.png

UIBezierPath* rectanglePath = [UIBezierPath bezierPathWithRoundedRect: CGRectMake(x,y,width,height) cornerRadius: 11];
[UIColor.grayColor setFill];
[rectanglePath fill];

Corner radius for top-left edge:

http://i.stack.imgur.com/OEOJa.png

UIBezierPath* rectanglePath = [UIBezierPath bezierPathWithRoundedRect: CGRectMake(x,y,width,height) byRoundingCorners: UIRectCornerTopLeft cornerRadii: CGSizeMake(11, 11)];
[rectanglePath closePath];
[UIColor.grayColor setFill];
[rectanglePath fill];

Corner radius for top-right edge:

http://i.stack.imgur.com/1xhp8.png

UIBezierPath* rectanglePath = [UIBezierPath bezierPathWithRoundedRect: CGRectMake(x,y,width,height) byRoundingCorners: UIRectCornerTopRight cornerRadii: CGSizeMake(11, 11)];
[rectanglePath closePath];
[UIColor.grayColor setFill];
[rectanglePath fill];

corner radius for bottom-left edge:

http://i.stack.imgur.com/yqd87.png

UIBezierPath* rectanglePath = [UIBezierPath bezierPathWithRoundedRect: CGRectMake(x,y,width,height) byRoundingCorners: UIRectCornerBottomLeft cornerRadii: CGSizeMake(11, 11)];
[rectanglePath closePath];
[UIColor.grayColor setFill];
[rectanglePath fill];

corner radius for bottom-right edge:

http://i.stack.imgur.com/AIgP0.png

UIBezierPath* rectanglePath = [UIBezierPath bezierPathWithRoundedRect: CGRectMake(x,y,width,height) byRoundingCorners: UIRectCornerBottomRight cornerRadii: CGSizeMake(11, 11)];
[rectanglePath closePath];
[UIColor.grayColor setFill];
[rectanglePath fill];

corner radius for bottom edges:

http://i.stack.imgur.com/4BrrS.png

UIBezierPath* rectanglePath = [UIBezierPath bezierPathWithRoundedRect: CGRectMake(x,y,width,height) byRoundingCorners: UIRectCornerBottomLeft | UIRectCornerBottomRight cornerRadii: CGSizeMake(11, 11)];
[rectanglePath closePath];
[UIColor.grayColor setFill];
[rectanglePath fill];

corner radius for top edges:

http://i.stack.imgur.com/lecWo.png