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 !!!
You can also travel to places in South India like Coorg (Karnataka), Bangalore (Karnataka), Ooty (Tamil Nadu), Hampi (Karnataka) and the whole of North East India (seven sisters and Sikkim)