Can these problems be solved by integrated design bureau planned by IA?
No.
Indian Army should have its own design bureau but this has nothing to do with it.
The sensors are Indian but the FPA is still most likely foreign or even at the very best (ie. if they are Indian) then at the same maturity level as the rest of the world. So if FPAs cannot work in that kind of heat and temperature differential then that is the problem of technology not being mature enough. Nearly nothing to do with DRDO's or Indian Army's competence or incompetence levels.
CCD sensors for Nag, have been talked about since long, which is a day or low light sensor. IIR is for day/night both. Chances are CCD sensor, for optical imaging, was not developed for logical reasons. Just get the MMW sensor to work.
Without MMW the only way Indian Army could have helped the cause is by accepting heavier Nags with both CCD and IIR sensors. Which will entail another long round of testing for nearly all parts of the system. Probably would have helped if the same was attempted from the get go. Unfortunately IA and DRDO are usually working at cross purpose.
Another option is to have a laser guided missile mated to the Namica. But for the IA that may sound risky.
So basically, while you can find options to fight even in the extreme conditions, the lethargy and bitter history and changing landscape of the battlefield will change quite a bit of the requirements w.r.t. Nag. UAVs with Helinas will not face this problem and at the time the Nag was being developed UAVs were not a big item on the list.
