Culprit was default hight of label.
label Default height
NSTextField Default height
below is code for Label with height 22
NSTextField *textField;
textField = [[NSTextField alloc] initWithFrame:NSMakeRect(10, 10, 100, 22)];
[textField setStringValue:@"My Label"];
[textField setBezeled:NO];
[textField setDrawsBackground:NO];
[textField setEditable:NO];
[textField setSelectable:NO];