Any place in Himachal will be a good deal, before June though. The weather will be pleasant, and with clear roads, you will be able to visit lot of places.
Personal choices - Mcleodganj, Dharamshala, Bir and Billing
Hey Anindita This is best Places in India you can visit From April to June 1- Manali ( Himachal Pradesh ) 2- Shimla ( Himachal Pradesh ) 3- Dalhousie ( Himachal Pradesh ) 4- Khajjiar ( Himachal Pradesh ) 5- Nainital ( Uttarakhand ) 6- Mussoorie ( Uttarakhand ) 7- Darjeeling ( West Bengal ) 8 - Ooty ( Tamil Nadu ) 9- Rishikesh ( Uttarakhand ) Happy Travelling !!!