Take a morning train from Delhi to Haridwar. Check into your hotel, visit famous Har Ki Pauri ghat to see evening Ganga Aarti.
Take a shared taxi or bus to Guptkashi, on the way you can stop at Deoprayag to see the Sangam. Check-in at your hotel and have a leisure day.
Drive to Sonprayag and trek to Kedarnath, visit the famous Kedarnath temple and stay overnight at Kedarnath.
Return trek to Sonprayag and drive to Guptkashi. Check-in your hotel and rest.
Drive to Rudraprayag, visit Rudranath temple and Chamunda Devi temple. Check-in your hotel and relax.
Drive to Rishikesh, visit Laxman Jhula and enjoy white water rafting. Check-in your hotel in Rishikesh and rest.
Drive to Delhi and check-in your hotel. Spend your evening exploring the city, and visit Red Fort and Chandni Chowk.
Take a morning flight back home from the airport.
If you have more time, you can visit Badrinath and Valley of Flowers. If you have less time, skip Rudraprayag or Rishikesh. Make sure to bring comfortable trekking shoes and warm clothes.