Getting longitude and latitude of location when touch in position in google maps in unity

I am new to unity. I am developing app in unity engine I am using unity 5 free version I have done map part. I want latitude and longitude of desired location. for that if i will touch in that position in google map it has to return latitude and longitude of that particular location. How i have to do this.

Thanks in advance

Have you looked at https://developers.google.com/maps/documentation/geocoding/#geocoding? Should be what you need.