The thing with submarine warfare is that it's a long game. Submarines are slow (especially true for SSKs) and can detect and engage targets only at short distances. This means that for submarines to play a part you need a war that lasts weeks and months not days which is what we saw in 2025.
If India wants to declare a maritime exclusion zone outside Karachi they can do so from over 600 kms away thanks to Brahmos and air launched weapons. We will be effectively blockaded. To break this blockade we need to take the fight to them, this is why I personally believe a defensive naval doctrine won't help us. Weapons like Taimoor are a step in the right direction. Submarine launched anti-ship missiles would be another.
Diesel electric submarines even those with AIP are most effective when defending i.e ambush enemy ships that enter your waters. This doesn't mean they can't be used offensively, PN did so in 1965 and then again in 1971 with mixed results. But if you employ them offensively you have to accept risk of losses. And it takes submarines a long time to show results as previously discussed.
Anyways, IN's submarine force will remain larger than ours until 2030 and even then they will inevitably catch up again. So we really don't have that much of an advantage there. I also think they can afford to use their submarine force defensively, while we will be forced to use ours offensively.