DRDO and the Air Force are doing a mistake by going for a MK2,it will be another wild goose chase. The problem of performance is not with the mk1 design but the requirement to stuff everything possible into the dense airframe of the tejas.The air force wanted everything the upg mirage-2000 airframe had into a smaller aircraft, they were in a delusion that they dint know what they wanted from this little aircraft, a gnat like fighter or a hawker hunter like fighter.
A good fighter meeting the ASR perfromance with the existing mk1 airframe can be achieved with minimum design changes.
1.First there is not need for multi mission requirement in the tejas(other aircraft can do it),it should have been made into an interceptor,point defence fighter agile at all altitudes and good at BVR within 50km.A compact,light radar with light weight missiles such as IRIS-t,derby(data-linked BVR unncecesary for 50km) should be used.
2.Reduce the max speed to between 1.4-1.5 mach(tejas will be out of fuel before it reaches 1.8M on afterburner even with tanks) just above the transonic-supersonic drag rise region.
3.Limit the supersonic manoeuvrability to 2-3g(a pilot cant sustain beyond that),limit subsonic-transonic g to 8g.These above changes will reduce the stresses on the airframe by a huge margin thus making the fabrication lighter and easier.
4.Use aluminium and fibre glass composites instead of carbon fibre,we just don't produce CFC but only fabricate them then why use a strategically vulnerable material(remember how the brits used wood in the de havilland mosquito).
5.All nav attack systems,mission planning systems,air to ground targeting pods,auxiliary power units to support them and other systems which are unnecessary for the above mission must be removed.
6. Optimise the air intakes for the predominantly used subsonic-transonic region , reduce the cross section of the tejas with the space created and elongate the airframe slightly so that wave drag is reduced(like what was done with the f-16xl).
7.Remove the heavy draggy racks installed for heavy bombs and drop tanks(except centreline for ferry missions).
8.Remove the excessive dead weights(ballast) which were installed to counter the above equipment.
9.Built in test equipment(BITE),condition monitoring equipment give a large number of false alarms which unnecessarily ground the aircraft,so use reliable,proven COTS BITE and health monitoring equipment only for critical equipment(such as engine,FBW).
10.All the aircraft need not have a air-to air probe,in combat only a few aircraft carry out missions which use air to air refuelling and esp not often by the tejas,so equip only a fraction of the fleet with this capability.
11.Design for supportability,reliability and manufacturability instead of perpetually chasing revised ASR.
If these changes are done with good care we can have an affordable,reliable,supportable fighter even with the 404 and the existing airframe, with which the airforce can fight.But if we are lost in the glamour of glossy fighters in magazines we are doomed.