Whilst I haven't been to the cricket in Kolkata, I was in Mumbai last December and decided to go to the cricket as it was nearby. It was Australia v India women's test. I literally walked there to take my chances. I was surprised to find no ticket office but only electronic ticketing. Someone kindly showed me how to download an app which everyone else seemed to have & you can pay by credit card or a local pay app and it was quick as a flash. So much more efficient than any sporting ground I have been to here in Oz. There were plenty of seats and the whole thing was actually quite a seamless experience. The only thing I would say was that as I wasn't familiar with either the app or the stadium I would have preferred better seats - they were available but I obviously just didn't think to look for them.. Have fun.