I was there in March a few years ago. Was retired from climbing at the time, so only pottered a bit on a few moderate boulders. But it was *hot*. Even locals were complaining.
Still, probably better than not going, it's an amazing place, and you can probably get some bouldering done if you climb early/late/in the shade. If you go, definitely walk up Matunga Hill or up to the Hamuman temple to watch the sunrise one day.
You said you will be in or near Mumbai or Pune? You may not have to travel so far. There are some pretty impressive looking bumps in the Western Ghats between Mumbai and Pune, and definitely some climbing in the area. I read something once about some huge horrendous Doug Scott aid epic; if you're not up for that you might get better beta, or find partners/guides for a weekend, by contacting
these guys.
(I'll be in Bangalore next week, tho sadly only Monday to Friday. I had already figured out that a weekend Bangalore-Hampi would be feasible but v.strenuous, involving sleeper trains Friday night & Sunday night)