Mike, I live in Bombay.
Most landlines in the city were down for several days. Since they rely on underground cables, they were severely distrupted because of the flooding.
Mobile networks, whilst not necessarily down, were jammed. That's not surprising, since even the homeless, beggars and vagrants have mobile phones these days!
That said, the southern part of the city, where I live, was largely unaffected. It did rain a lot, certainly, but I only found out about the havoc when a friend called, asking to stay over.
If your friend's phone number starts with one of these, you should be able to reach him/her:
Anything else will still be a hit-or-miss.
All the best!