Hey Nisha, Tripoto has some curated trips for short weekend trips near Mumbai. You can find them below attached with my comments. I hope this helps. Thanks!
Hey Nisha, there are a couple of places you could explore around Mumbai. Lonavala, Panchagani, Pavana Lake, Matheran, Lavasa, Elephanta Caves. If you're looking to travel somewhere around this time, Bhandardhara should be a good option as they have a lot of night treks where you get to see fireflies. A couple of places in Mumbai that you'd love to see would be Haji Ali Durgah, Marve and Aksa beach near Malad - they have some real good and reasonable resorts there and the beaches are comparatively cleaner and quieter.
Check out Bhandardara, dist. Ahmednagar. It's an amazingly beautiful place. There's mountains all around. Bhandardara is situated in the midst of Sahyadri range. You must visit this place once at least. Check out The Land Of Wanderlust (TLOW) website..... https://thelandofwanderlust.com/