Sorry to burst your bubble again, but with increasing education and living standards, fertility rate is drastically falling. Not every muslim family has 5-6 kids. As per stats, the average number of kids for a Hindu family is 2 and for a muslim family is 3. As per the latest projections, Muslim population will stabilize to around 20% of the population by 2100 with no increases afterwards. It's not only because they want to have less kids but also because they cannot afford to have any more. Pooping out kids is easy, but you have to feed them too to survive and there comes the hard part. In the 1950s and 60s it was easy. Have as many kids as you want, there is ample land, ample water, just squat anywhere. No longer the same. A small plot of land required to support a family costs lakhs.
Keep having 5-6 kids and let's see how it turns out for Pakistan
. Stupidity has no bounds but the amount of water and food on the planet does have bounds. Neither is there enough land in Pakistan to support food for that amount of population, neither is there any water. Indus river, the source of 90% of your water is already the most stressed river in the world. There is simply no more water in it. And not only is it stressed, it is also doomed. Himalayan glaciers are expected to be "kaput" by 2100.