Having cultural sensitivity is very important. When I first ventured into Durga puja I was completely taken aback by the non-vegetarian dishes being served near the Pandal. But now I love every time there is Durga puja pandal in Powai.
Chhath Puja is something I don’t know more about, but as per Wikipedia it’s an ancient Vedic festival celebrated mostly in the north Bihar and Uttar Pradesh. We see lots of people around Powai lake during this time. This video doesn’t have a explanation, but the quality of the video is good enough for you to experience what happens during the day kong chhath puja celebration at Powai lake.
For more info check Wikipedia