Talking of upgradation of current cobra helicopter of Pakistan Army, precisely we need upgradation in two areas
Avionics and Weaponry.
Now Cobra has primery weapon of TOW, which is a wire guided missile. Its maximum range is 3.75 km (because the length of the wire is 3.75 km).
The T-72 and T-90 are now able to fire Laser beam riding missiles 9M119 missiles through their 125 mm smmoth bore guns. The max range of the missile is 6 km. which means T-90 has a better stand off range then Cobra helicopter. Cobra has to first detect a threat, identify it prioritize the target, come to a hover and then fire the missile. At max range, TOW takes around 20 sec to reach 3.75 km range. I dont think a troop of T-90 would be so gracious to give to much time to cobra helicopter. T-90 missile will target cobra earlier then TOW hitting tank.
9M119 Svir - Wikipedia, the free encyclopedia
125 mm 9M119 and 9M119M gun-launched missile round (Russian Federation) - Jane's Ammunition Handbook
So when talking of upgradation, anti tank missile is to be replaced with a better range missile. Pakistan should ask USA to provide TOW 2B aero having a range of 4.5 km. as its descendant of TOW family, it can easilly be integrated to present fleet of Cobra helicopters.
http://www.raytheon.com/capabilitie...uments/content/rtn_rms_ps_tow_2bdatasheet.pdf