Thanks for the detailed answer and it does highlight a need of more aircraft for coastal and waters defence.
I have been thinking in terms of strike. There was a guy here, Naif al Hilali (credit goes to him), he calculated combat radius for different JF-17 mission profiles.
If you are looking for aircraft to reach out to Mumbai from say karachi which is somewhere around 900 km aerial distance, even JF-17 can do that for a strike mission on installations with profile:
Internal Fuel + Two 1,100 Liter Drop Tanks + Targeting Pod + Two 1,100 pound Precision Guided Bombs + Two PL-5EII
Roughly 1050 km mission radius. I am guessing F-16 Block-15 MLU range could be more. JF-17 Block III range (in terms of internal fuel capacity) is expected to be more
As for double engine aircrafts; will two engines consume fuel quickly than a single engine, shortening range ? Or getting quickly at super cruise altitude could save fuel.
For an Anti-Shipping Mission:
Internal Fuel + 800 Liter Drop Tank + Two CM-400AKG Anti-Shipping Missiles + Two SD-10A + Two PL-5EII
Around 450 km mission radius.
Internal Fuel + Two 800 Liter Drop Tanks + One C-802AK Anti-Shipping Missile + Two SD-10A + Two PL-5EII
Around 690 km mission radius.
Internal Fuel + Two 800 Liter Drop Tanks + Two C-802AK Anti-Shipping Missile + Two SD-10A + Two PL-5EII
Around 465 km mission radius.
So for Range of CM-400AKG missile, around 200 - 250 km ? or 300 km? Lets say JF-17 fires at range of 200 km (i'm not sure if its radar dependent and then radar range would allow), its still a decent distance to keep IN ships away from Pakistan Ports.
Will PN subs keep IN ships at a distance greater than what JF-17 can project ? most probably yes.
The submarines will need help from planes and in order to prevent a blockade this will be needed to deal with the IN surface vessels. Remember Poseidon need to be countered to protect subs
how far can JF-17's reach to protect PN subs
Long-Range Interception (/Air Superiority/Fighter Escort):
JF-17 Block I/II
Internal Fuel + 800 Liter Centerline Drop Tank + Two 1,100 Liter Drop Tanks + Two SD-10A + Two PL-5EII
Mission Radius is 1150 Km. (even 1400 km Range is reported in CAC assessment)
How far and how long can JF-17 remain stationed on CAP without refuel.
Combat Air Patrol [CAP] 350-380 km from base
JF-17 Block I/II
Internal Fuel + 800 Liter Centerline Drop Tank + Two 1,100 Liter Drop Tanks + Two SD-10A + Two PL-5EII
1 Hour 50 Minutes without refuel.