Hi, Ayan!
Places like Spiti Valley, Tirthan Valley, Gulmarg, Mcleod Ganj, Nainital, Mussoorie, Gangtok, Tawang, Shillong, Cherrapunji, Mawlynong, Darjeeling, Coorg, Kodaikanal, Munnar, Matheran, and Lonavala are some really great places to enjoy a holiday with friends in the month of May. These place offer amazing weather conditions and spectacular views of natural beauty that our country is home to.
You can also check out following Tripoto links to help you decide a destination to travel to with friends in May:
https://www.tripoto.com/trip/best-places-to-visit-in-may-in-indiahttps://www.tripoto.com/trip/best-places-to-visit-in-summer-in-india-56cc844facd72
Hope that helps!