Small arms in India are a complete mess.
Standard lmg:
negev (5.56)
GPMG:
FN Mag (7.62)
Standard sniper rifle:
Galil (7.62)
The Insas rifles, lmg, FN Fal, Bren lmg, AKs, and PKMS are JUNK and need to be decommissioned (maybe give insas to police)
Well one need to see how practical your dream is, Also one need to understand what is mess:
LMG:
Should have both belt feed also MAG feed, LMG are preffered with MAG feed, IMI use Nagav also with MAG, It is lighter and help firing when Charging, The LMG should have common parts with Rifle & GPMG
GPMG:
You Dont know that PKM barrel is thicker which helps it to cool fast also PKM is lighter than FN-MAG, So does its more easier to maintain than FN-MAG, The GPMG should have common parts with Rife & LMG.
Standard Sniper Rifle:
FN-FAL can be modified for the purpose, The Sinper Rifle too have common parts with assault rifle and LMG so with GPMG..
Insas Rifle & AKM will be replaced by FINSAS rifle, PKM is good, Bren is good enough untill they are replaced by something what i mentioned, I think Police should be given AKM not Insas, Police are used in Urban, the range they use is not more than 50m..
To remove the Mess, All firearm should have a base platform, All fire arm should share common parts with other fire arm in service..