There are a lot of parties happening on the 31st. I would suggest you to narrow down your search to the kind of party you are looking for based on the music genre, location and cost. Feel free to revert with questions.
Hi Dious, You can do following things . 1. Spend the day At Bannerghatta National Park
2. Go pub-hopping at Brigade Road / M.G
3. Explore Lumbini Gardens Also you can organize in house party. Happy Travelling! Thanks,