Ohk so your idea is to create a partisan/guerilla in India,and you are asking which weapons are good for such armed group.
My thinking is,proliferation plays a key role in such situation,so the weapons going to be deployed in such situation would have to be made in such calibers which could take already available ammo in mass amount + if they can take magazines commonly available in large amount then it's another jackpot.
Some ideas i've had in my mind is..
for Pistols,I think two rounds are good,9 x 19mm and 7.62 x 25mm
hence,my choices would be,
for 9 x 19mm,Browning Hi-Power and Colt 1911 (there are variants of this gun chambered in this round)
^Both these guns are quite simple in design and i think magazines won't be much issue as well,
for 7.62 x 25mm,Tokarev Pistol,of course
alternatively,a single platform for both calibers which could take already existing magazines.
My choice would be Tokarev,standard one and a special 'jugadu' one chambered in 9 x 19 which could take staggered-column browning hi power magazines
one example of 9 x 19mm Tokarev,Serbian Zastava M70AA
http://www.zastava-arms.rs/en/civilianproduct/m70aa
for sub-machine guns,i would say,
Sten Gun/Sterling SMG for 9 x 19mm,
Uzi for both 9 x 19mm and 7.62 x 25mm (like this Uzi in 7.62 x 25mm
)
^These open bolt guns are easy to manufacture (yes,including Uzi) and mags won't be much issue as well.
for assault rifles,
Kalashnikovs,no doubt,chambered in 7.62 x 39mm.Both rounds an magazines are easy to found
in 5.56 x 45mm,one could be made which could take INSAS magazines,after all,INSAS is a kalashnikov derivative herself.Maybe an Excalibur type gun for this one.
for full length rifles,
I say prefer to 7.62 x 51mm NATO guns,and my choice here is definitely FN FAL
Although heavy,but quite rugged and with scope it could also act as DMR,plus magazines are easy to find.