I am no expert in fishing but here is what i have seen in a dam near Pune
The local villagers throw fish waste (guts, liver etc) into a section of the lake where there is more mud than rocks. After some time they come back to the place and put a used old cotton 'Sari' at the bottom. Then they put some more of this bait on the top. within minutes 2 people gently lift up the sari and take out quite a few prawns.
However these prawns are mostly used as live bait for eels, murrels etc
I am not sure if anyone can catch a prawn with a rod, but it would be interesting to know, if possible, how it is done