Actually with careful snooping, real-time intel, tactics and contingencies, tis possible for the IN to sink the entire principal fleet of Pak in a matter of 48 hrs. The killing wouldn't take more more than few minutes each time.
Smartest thing we can do now is to order more ATV, I would say atleast a fleet of 20-30 of these home made subs should be the norm, i think instead of wasting money on the rafale, a mass order of the atv in both nuke and AIP variants while deploying the Sagarika, Brahmos, nirbhay on them would turn every navy's worst enemy