Take 3 Li-on batteries to Nepal from China with the capacity of 3000 mAh and 3.7 voltage each.

Well, you cannot take lithium batteries in the checked luggage. Generally speaking, at most two spare batteries can be carried as hand luggage. 100wh is for each bettery you take, not for batteries in total. Thus according to this regulation, the capacity of batteries will be ok. But you can only bring 2.