Just like in a Fifa world cup, all the continents are represented, same is the case with basketball world cup. Maybe in future India and Pakistan will represent in the FIBA . It is the famous sports but it is not so popular in Sub-continent.
Basketball is not that unheard of in India and Pakistan. In India we have a franchise based basketball league, which is quite popular among the fans. But the real reason is that the Indians are not athletic enough to compete with players from the United States and Russia. Average height in India for males is 165 cm, which is 11cm lower than the case in the US.
One of the options is to import some second tier players from countries such as US and get them naturalized as Indian citizens. But I don't prefer that route.