I want to apply for a tourist visa, what are the requirements of tourist visa?

The documents for tourist visa application are listed as follows:
1. one appropriately and authentically filled
visa application form.
2. your passport valid for at least six months with at least 2 blank visa pages.
3. One recent passport size photograph.
4. One Passport photocopy
5. Covering letter from applicant's company or employer addressed to the visa office.
6. Photocopy of a confirmed return air ticket
7. Foreigners other than Indians should have valid Indian visas or valid Residence Permits in India.
8. you are requested to supply proof of travel expenses.
Normally, the duration of a single entry tourist visa is 30 days.