For the stock brake pads that comes with the car, does the rear or front one wears off first?
brake on front wheels normaly called brake pad and those in the rear drum called brake shoe.
Since Latio fis ront wheel drive so brake pad wear off first.
Brake shoe got 2 pieces each side. One peice will wear off faster than the other piece because the one nearer to your boot only active when you use parking brake (leg brake).
When it wear off? IMO, don't have to follow 40k change front pad, 80k change rear shoe as each of us use the car differently. If you notice your brake not as good as before or the braking distance get longer. Then it is time to check/service your tyre and brake system else just use it.