I have used Zig Rig in its origonal form and as you rightly guessed, I have my own version of Zig Rig to match the requirment of Powai. Zig Rig with one Boily on will not work in Powai... You have to modify it by adding a feeder insted of simple float.
I am not sure about the type of insect Catla Feeds so can not help you here.
Spodding is not neceserry here. In case you want to play far, I have spods and you can use them.
Here is a small writeup on the habits and Habitat of Catla and I think it may help you to formulate your plan.
One of the most difficult fish to catch, and the hardest fighting Indian Carp, Catla (Catla catla) is the only member of genus Catla, from the carp family Cyprinidae. This fish is commonly present in rivers, lakes and ponds throughout India. Mainly a surface feeder, this fish feeds on plankton, Zooplankton, Insects, crustaceans and plant material (Ref. Site http://arccjournals.com/pdf/Animal/41-4 ... -4-006.pdf
). Crustaceans consists major part of the food but the interesting part being the high percent of insects (8.082%) in its food chain, opening up the possibility of targeting this magnificent fish on a fly rod also. As evident by its large protruding lower jaw, it is evident that this fish feeds by filtering a lot of water through its mouth and as we will discuss later, using fast dissolving bait and a critically balanced open hook is best bet to target this fish.
Many studies have established that the feeding intensity of this fish remained high during non spawning and post spawning period of winter and monsoons but reduces during spawning period of summer. The fish feeds voraciously just after spawning to recover lost weight during spawning period.
The IGFA world record for this fish is only 15.4 Kg. but catches as high as 36 kg. have been reported (From Powai Lake, Maharashtra). There is no authentic record of Catla growing over 38.6 Kg. but unauthentic reports suggest that this fish can grow much more than that.
The other common name of this fish are Bhakur, Chepti, Boassa and Katla in Hindi, Karaka, Karacatla and Katla in Malayalam, Catla, Katla, Kendai, Theppu Meenu, Kanavi, Yamaneri endai and Karavai in Tamil, Botchee, Botchi, Botcha and Krishnabotcha in Telugu, Katla, Pla Kra Ho in Bengali, : Tambra, Katala, Pla Kra Ho in Marathi, Bawas, Tambra, Thambra in Gujrati, Theil ,Theila, Thaila in Punjabi, Bahkur, Barkur, Bhakur in Oriya (Ref. Site http://www.knowmyindia.in/?p=90
For Common Names of this fish Please Refer : http://www.fishbase.org/comnames/Common ... kCode=4637
For further detalis or Identification please refer: http://www.fishbase.org/summary/Catla-catla.html
Further I would like you to pondor on the best rig for a floating setup. A good rig coupled with a feeder can give you lot of sucess here..