According to immigration rules, a work permit for India is synonymous with an employment/business visa.
Expats wishing to work legally in India first need to obtain this valid Indian visa before beginning their job: no separate work permit is needed.
DETAILS
Foreigners can apply for a tourist visa if they are coming to visit friends or for sightseeing.
Tourist visas are generally granted for six months at a timE
Anyone who has an Indian tourist visa must have a two-month gap between visits to India.
So a tourist visa holder can return to India only after two months of leaving the country.
Foreigners are not allowed to work in India while holding a tourist visa. very important .
Work visas for India
Business Visa
Employment Visa
Business visas in India
Business Visas are available for people who wish to explore business opportunities or conduct business in India.
This type of visa differs from an Employment Visa,
in that the applicant will not be working for,
and earning an income from, an organisation in India.
Instead they will be working on behalf of a company outside of India.
Business Visas are generally issued with six month validity or more, and provide for multiple entries.
However, holders of a Business Visa are not allowed to remain in India for longer than six months at a time.
Employment visas in India
An Employment Visa, on the other hand, is issued to a foreigner who will be working in India for an organization registered in India. Foreigners wishing to do volunteer work in India also require this category of visa.
An Employment Visa is valid for one year, irrespective of the duration of the contract.
Applying for a visa for India
All foreigners coming to India for employment should apply for a valid Indian visa before they arrive.
You can obtain a visa application form from the Indian Embassy in your country
Documents required for visa applications
â–ºEmployment Visa
  Proof of employment with a company/organisation in India, such as a contract that states the terms and conditions of appointment.
  In 2010, the Indian Government included a new requirement - visa applicants must be earning 13,75,000 Rs a year or more.
Exceptions are made for members of foreign high commissions and embassies.
â–ºBusiness Visa
  A letter from the organization they intend to do business with, stating the nature of business, duration of stay, places to be visited and the employer's intention to meet expenses.
â–ºTourist Visa
  Passport with a minimum six-month validity
  Recent passport-size photographs
  Details of your itinerary
You can expect to get your Indian visa in between five and seven working days.
In addition to the above, each category of visa requires additional documents.
â–ºBusiness Visa
  Letter from the person or firm in India with whom you intend to do business with, indicating type of business, volume of business in the current year, etc.
  Contract or assignment letter from the company
  Bank statements showing assured financial standing
  Copy of Bill of Lading or invoices
Visa is valid for 6 months AND NOT 1 MONTH.GET UR FACTS RIGHT
YOU CAN OBTAIN A VISA APPLICATION FORM FROM THE INDIAN EMBASSY IN YOUR COUNTRY .