You can visit Lahaul Spiti in summer for 3-4 days. The place is also known by the name Himalayan Desert. You will get to see beautiful scenic beauty and I am sure you are going to love it. Also, you can prefer for snow trails camp if you are adventure buff and indulge yourself in adventurous games.
Hi Anusha, Ooty and Kodaikanal are best trip places during summer. There are many hiking spots, falls, rose garden in ooty etc which can be covered within 2 days.
You can visit kalpa! it's around 200 kms from Shimla .great for a road trip and adventure! going to regular hill stations like Manali ,Shimla feels so crowded at this point of time .
I would tell you personal fav for short budget and time trips, tosh would be a perfect t place to enjoy your time and relax, its totally alienated from the rest of the North!
You can go to 1)Panchmari in Madhya Pradesh, it is a very beautiful place.
2) Ooty (South)
3) Mahabaleshwar (Maharashtra)
4) Matheran, Maharashtra. It is not exactly a hill stations but a very beautiful place.
5) Mount Abu, Rajasthan
If you want to experience snow then : Gangtok, Pelling, Lachung in Sikkim Manali
Auli in Uttarakhand
Other than that: Darjeeling
Meghalaya
Coorg
Munnar
Ooty
Munsyari, Uttrakhand.
In this trip you can cover Bhimtal, Naukuchiyatal, Binsar, Nainital, Patal Bhuvnesgwar & Chokori. Awesome weather, view of Himalaya with Panchachuli.