not just inducted ones with Army.. want to know if some promising development going on. Sandip Unnithan's Videos are showing JVPC and 7.62 51 as good. If para and other SF have accepted the guns you mentioned, what is army's requirement that is not being met by these guns but is being met by the INSAS?
It's not that INSAS is better than the other recent designs of OFB/DRDO, it's just that INSAS was inducted 20 years ago and is the incumbent.
Most other assault rifles designed by OFB/DRDO are an improvement over INSAS, but Army feels that the improvement is not sufficient enough.
After having decided on the required caliber, range & rate of fire etc, armies normally test the rifles on the basis of accuracy, reliability (numbers of rounds fired before jamming), weight, ability to accessorize etc.
The final decision on an rifle is normally based on some weighted average of all its attributes.
From a development process, its always iterative. Test, find flaws, fix - & repeat cycle. IA is known to send weapon systems back to drawing board & test cycles for minor adjustments. All of which is fine if all of it is done within the available timeframe. It's all a matter of the system's ability to mature before IA's absolute deadline for inducting a new system.
Paramilitary forces firstly come under a different ministry - their available budgets are different & the decisions made by them are independent of IA's. Secondly army has a different fighting doctrine compared to the paramilitary. As such the choice of weapons could differ. (IA would be expected to be more stringent in their choice)