Pakistan and India are both accusing each other of supporting the Taliban. How can this be? In the case of Pakistan, it's no secret that Pakistani military intelligence helped form the Taliban in the early 1990s, to provide a more disciplined force that would end the civil war in Afghanistan. Civil war in Afghanistan was causing more refugees to head for Pakistan, which didn't want more refugees, or a neighbor that was suffering a seemingly endless civil war. Many Afghans believe that Pakistani intelligence (the ISI) is still providing some support to the Taliban. This is uncertain, although it is likely that Pakistani intelligence maintains their old Taliban contacts because, well, that's what an intelligence organization does.
The Indian connection comes from Pakistani accusations that Indian intelligence is supporting Baluchi tribal separatists in southwest Pakistan. This is rather more murky. The Baluchi tribes have been trouble for a long time, and never indicated any reliance on outside support. But the Pakistanis are leaning on the Afghan government to crack down on Indian diplomats in Afghanistan, who are believed providing support (money, information) for Baluchi tribes just across Afghanistan's southern border. The Pakistanis insist that the Indians have also worked with the Taliban, who are sometimes allied with pro-Taliban Baluchi tribes. It is known that there are pro-Taliban Pushtun and Baluchi tribes, but this is more the result of shared preference for Islamic conservatism. There is also a problem with the Taliban working with India, which is seen as an "enemy of Islam" (most Indians are Hindus, a religion that has been persecuted by Moslems for many centuries.) What is certain is that Pakistani and Indian intelligence operatives are very active in Afghanistan.