You can go for Kasol-Tosh-Pulga. From Delhi book bus through HPTDC to Bhuntar. From Bhuntar take local buses to Kasol. Stay 2days over there. On 3rd day go for Tosh via covering Pulga. You can stay at Pulga or Tosh. on 4th day take bus from Bhuntar to Delhi
You can visit any of the following :
1. Shimla
2. Amritsar
3. Dehradun Mussoorie
4 Haridwar & Rishikesh
5 Jaipur 6 Kasol
7 Dhanaulti
8 Mt Abu 9 Udaipur
10 Dharamshala
You can visit any part of India in that budget. For some international options, Nepal, Bhutan, Sri Lanka, Thailand (Bangkok-Pattaya-Phuket-Bangkok) and Dubai is possible, provided you book the flights for the last two at least 4 weeks in advance.
You can visit Darjelling, Gangtok with this budget. you can take flight from Delhi Airport to Bagdogra and Darjelling is 67 km (2hours drive) from there.
In this money u can see the best of Indian places like
Kerala
North East of India
Rajasthan ( Jaipur, Jodhpur, Udaipur, pushkar, jaisalmer)
Kashmir Leh- Ladakh
Andaman Islands ( for solo trip)
Lakshdweep u can even have trip to our neighbouring countries like
Sri Lanka
Bhutan
Nepal
You can go for Kasol-Tosh-Pulga. From Delhi book bus through HPTDC to Bhuntar. From Bhuntar take local buses to Kasol. Stay 2days over there. On 3rd day go for Tosh via covering Pulga. You can stay at Pulga or Tosh. on 4th day take bus from Bhuntar to Delhi