What you are referring to is a "loyal wingman" air launched drone, which IIRC China is developing for the J-20.
A simple EMP attack/jamming can render this unmanned JF-17 uncontrollable - that is, unless you can program it to be completely autonomous, something even the US and China are yet to achieve for a small drone, let alone a whole fighter.
You will have to go through the headache of securely communicating with this aircraft too. Iran could hack a US drone and land it, allowing them to reverse engineer it. Imagine if the Indians got their hands on our frontline fighter with some of the best Chinese technology (EW suite, radar, PL-15 etc.) Or imagine if they hacked them and turned them into suicide drones with PL-15s.
Otherwise, you will have to program a computer which is aware of when to turn its radar on or not, how to IFF, which target to lock against all the clutter, which is the best setting to use, how to take off and land, and a whole bunch of other stuff a human does without much fuss. Again, this is a very difficult task and I doubt Pakistan has the resources, knowledge and skills to make a reliable and secure AI this advanced.
This is 6th generation technology and beyond the scope of the JF-17. In fact, the ground clearance isn't even sufficient to carry a RAAD, let alone a whole drone.