Currently, Pakistan's Navy has ten subs, which suggests their submarine fleet could expand by 80 percent upon delivery, expected in the mid to late 2020s. Relations between both countries are incredibly complex, as the Kashmir conflict and the numerous military disputes on the Line of Control (LoC) have intensified in recent years.
According to unnamed sources, as quoted per Zee News, under Project Hangor, China's shipbuilding industry could soon be delivering over eight new subs to Pakistan. India's underwater warfare program is perceived to be far superior to Pakistan. As of now, India has sixteen submarines while Pakistan has about ten. However, China wants to scale up Pakistan's underwater warfare capabilities to defend the China Pakistan Economic Corridor (CPEC).