Welcome to Mumbai David.
Powai has the potential to be a world class fishery and holds some monster carp. They are about the shyest you'll come across and crabs gobies and mangur will have your bait before a Catla would ever get a chance. Only a masochist or a pathologically deluded optimist would ever fish there - so if you fit the description, welcome to the gang
Seriously, Ali has done a lot of trailblazing at Powai and it would be a pleasure to show you what little we have learned and pump you for some tips from the UK. PM me and I'll see if I can set up a session.