Nepali tourist visas can be obtained at various border crossings and at Tribhuvan International Airport, Kathmandu airport. Visas can also be obtained at the nearest Nepali Embassy. A valid passport and one passport sized photograph is required. Please note credit card, Indian Rupees and/or Nepali Rupees are not accepted as forms of payment of visa fee. Please check to see which currency is accepted.
Multi entry visas are granted for (i) 15 days (ii) 30 days and (iii) 90 days
For more detailed info please login to http://www.nepalimmigration.gov.np/
They have recently introduced online visa application too.
For Indian National
While Indian nationals do not require a visa to enter Nepal they must carry one of the following documents:
1. Indian Passport
2. Driving License with photo
3. Photo Identity card issued by a Government Agency
4. Ration Card with Photo
5. Election Commission Card with Photo
6. Identity Card issued by Embassy of India in Kathmandu
7. Identity Card with Photo issued by Sub- Divisional Magistrate or any other officials above his rank
Also, please check with your nearest travel agents for documents required by the Indian Immigration for Indians travelling to Nepal