Thank you @Sakib Pathen for explaining it week after week. Now, I am able to modify the current mirror script and add one more pmos (arbitrary). I am able to place the 3rd pmos as per my wish, horizontally or vertically, with proper separation. I am able to resize the tap ring as well to enclose the whole circuit. All by programming, it's amazing. It's a new paradigm of analog layout. (GF180)