The new Gmail interface look like this:
In old interface there is drop down button under mail where we can delete contacts. Now it is missing in new interface.
Classic Gmail (old version) had a drop-down at the top-left under Gmail for quick access to Contacts. Now this drop-down option has gone from new interface.
In the new interface you can see an square box on top-right near to bell icon. This has various Google applications:
Click on this square box, Contacts will be there, if its not there click on More, you will find the Contacts:
You can rearrange these products anytime by dragging them.