Udaipur, Udaipur and Udaipur! Well it will turn you speechless and then into a storyteller! It offers serene nature, fantabulous lakes, rich culture, ancient havelis and archeological sites like kumbhalgarh(2nd great wall of the world). One can even experience everthing in this spellbinding city from streetfoods to 7 star ambience food!
North East of India (Darjeeling,Gangtok)
Ladakh
Kerela (though not the best time again)
It is suggested to go to cooler hillstations in summers...Nainital,Shimla,Dalhousie,Mcleodganj,Kasaul,Kasauli,Auli,Manali,Musoorie
There are many places . Depends upon your starting point and the overall budget.
To name a few :
1. Dharamshala , Shimla , Landour , Nainital , Mussoorie , Gulmarg and Patnitop in North India
2 Coorg , Ooty , Yercaud and Kodaikanal and Munnar in South
3 Tawang , shillong , Gangtok and Darjeeling in North East