You will get around 8-10 servings, depending on the size of the serving dish.
You can use any biscuits that you use for layered puddings, instead of ladyfinger / tiramisu biscuit. You can also use pound cake/ sponge cake instead of biscuits. Alternatively, you can skip the biscuits / cake completely and just this as mango mousse cups.
You can use more mangoes while layering the pudding, in addition to the bottom and top layer of mangoes, you can add one in the middle too.
You can use china grass / agar agar instead of gelatine.
If you prefer a more creamier / richer pudding, you can use evaporated milk instead of regular milk.