We know that one of the upgrades being considered for JF is a FLIR/IRST sensor, removing the need to carry IRST/FLIR pods on the hardpoints. But an IRST/FLIR sensor would add a small amount of drag to the airframe if fitted in a similar spot as on J-11 or Typhoon, i.e. above the nose, offset to one side slightly. It may also cause some small reduction in pilot visibility.
Placing the sensor underneath the nose/fuselage would prevent any reduction in visibility, but the drag penalty would still be present. This position may also cause problems in aerodynamics for anything mounted on the centre hardpoint (and other fuselage hardpoints, if pshamim's report that two additional hardpoints will be added "on the fuselage near the air intakes" is true).
After looking at some pictures of the front of JF, I noticed that a possible solution may be to fit FLIR/IRST sensors inside the JF's divertless supersonic intake bumps. The tip of each bump appears to have a good field of view:
Front view:
1833502584_f3014856d8_b - Pakistan Defence Gallery
Front and to one side:
JF-17 Thunder - Pakistan Defence Gallery
Side view:
235 - Pakistan Defence Gallery
One more view from below:
JF-17 Thunder - Pakistan Defence Gallery
The view above the aircraft is restricted because of the angle of the intakes, however:
JF-17 Thunder - Pakistan Defence Gallery
Installing two IR sensors (one in each bump) may cause a higher increase in weight than a single external FLIR/IRST pod, but I think this is a price worth paying to free up an extra hardpoint and reduce drag on the small airframe. Close proximity to the fuel tanks would also mean less coolant lines required to send coolant for the sensors to heat-sinks placed in the fuel tanks.
Thoughts?