Solo traveler to Mumbai. How to meet other travelers or places to socialize.

I’m a young adult male visiting Mumbai from California for 6 days from Dec 31. I’d like to meet other solo travelers or socialize at places that are easy for solo travelers to make friends. Are there any groups, companies or communities that help with this? Id like to explore the city landmarks and nightlife. Also what is a good place to celebrate new years as a single guy where i don’t stick out as some awkward weirdo. I don’t plan to stay in the hotel room on NYE so that’s not an option. Any recommendations on upscale parties and expat crowd?