There are many popular Rivers of Nepal for Rafting:

• The Trishuli River (grade 3+)
• The Kali Gandaki (4-4+)
• The Bhote Koshi (4-5)
• The raging Marshyandi (4-5)
• The Karnali River (4-5)
• The Sun Koshi (4-5)  

Are the major rafting rivers in Nepal, all concluding at Chitwan making it an ideal way to visit a jungle camp rafting is possible from 1 to 10 days. 

Trisuli River:
The Trisuli river flows from Gosainkund where according to legend it is believed that Lord Shiva released the waters of the holy lakes with his trident (trishul). After its first confluence to the Mahesh khola, Trisuli River follows the Trisuli valley to Mugling and later again in confluence with the Marshyangdi rivers, this large river thus formed flows South to become the Narayani river. Most of the rafting in Nepal is done on this part of the river, which finally emerges at the Royal Chitwan National Park and more info please

Total River days - 1-4
River Grade - Class 4
Best Season - Late Sept. through May
Rafting starting point : Beni -Narayanghat
Rafting ending point : Narayanghat
River Distance : Approx. 70Kms.

Kaligandaki River:
The early day transfer to Pokhara and overnight stay at hotel after pre-departure briefing. Next day drive three hours to Nayapul, Kusma by mini coach. Start five days Kaligandi Rafting. On fifth day, after lunch drive back to Pokhara by mini coach.

Total River days - 5
River Grade - Class 4
Best Season - Late Sept. through May
Rafting starting point : Nayapul, Kusma
Rafting ending point : Ramdighat
River Distance : Approx. 92 Kms.

Karnali River :
The first day Bus to Surkhet and two days trek to Karaleghat, the rafting starting point.
The next day, start rafting five days. Whitewater and three days calm section. Raft ends at Chisapani.

Transfer to Kathmandu or Royal Bardia National Park .
Package Duration - 12 Days
Travel - 2 Days
Trekking - 2 Days
River Days - 8 Days
River Grade - Class 4/5
Rafting starting point - Karaleghat
Rafting ending point - Chisapani
River Distance - Approx. 180 Kms
Minimum 4 pax, usual transfer.

Marshyangdi River :
Transfer to Besishar via Dumre, camp at Beshisahar. Raft starts from second day
through fourth day. On fourth day transfer from Bimalnagar.

Duration of trip - 4 days
River Grade - Class 4/5
Best Season - Mid March to mid April, Mid Nov to mid Dec.
Rafting starting point - Beshishar
Rafting ending point- Bimalnagar
River Distacnce - Approx. 43 kms.

Sunkoshi River :
Transfer to Dolalghat and start rafting on one of the world's ten best river Sunkoshi. The first two days full of fun and rest of the days whitewater class IV/V rapids. Raft ends at Chatara Transfer to Kathmandu via Dharan.

River Days - 8
Trasfer - 1 day
Rafting starting point - Dolalghat
Rafting ending point - Chatara
River Grade - Class IV/V
River Distance - approx. 272 kms