Question

collect information about gravity at different locations like mountains,hill stations&countries​

Answer 1

This question is a hit twisted. This is because according to  Newton's laws of Gravity  i.e also known as universal law of gravitation, the gravity is considered as same at all places, i.e in hills, mountains, stations and in various counties.

This is considered as 9.8 m/s² for convenience.

So it does not matter where we go, within earth the value would be same everywhere. So it does not change from place to place.