Time Zone -: India is 5 hrs 30 minutes ahead of GMT (Greenwich Mean Time) in the winter months India is 4 hrs 30 minutes ahead of GMT.

General Essential Document
All visitors to India must be in possession of a valid passport. All visitors also need visas, except citizens from Nepal , Bhutan and the Maldives .

Carry your passport with you at all times.

Visas can be obtained from the Indian Embassy or High Commission in your home country. Ask for a multiple-entry visa, in case you want to make a quick trip to a neighboring country. 

Visas are usually issued without much difficulty if you meet the application requirements. These are: sufficient funds for the duration of your stay, a valid passport, ID photos, and a company letter for business travelers. The length of visas varies, allowing visitors to stay in India for anything from 15 days to six months.

In addition to a visa, you may need a special permit to visit certain protected or restricted parts of the country, such as areas in Sikkim , Ladakh, the Andaman Islands , Lakshadweep and some northeastern hill states. Permits are available at foreign registration offices, immigration offices, and Indian Embassies, Consulates and High Commissions. For Sikkim you will need a trekking permit. If you have a visa for Bhutan , you'll also need a transit permit to cross the border. This permit is available from the Ministry of External Affairs.

Public Holidays
India has a wide range of holidays and festivals, due to its religious and regional variations. Most Indian holidays follow the lunar year, so the dates vary from year to year. It is best to check the dates of the public holidays with an Indian embassy or consulate before traveling

Peak Seasons
The peak tourist season is from mid-September through to March, as the cooler winter months are from November to February. But as long as you take the weather into account, India is a year-round destination. Expect crowds at popular tourist spots and be sure to make reservations well in advance.

September to March is the best time to visit the plains and the southern regions. If you want to visit the northern Himalayan region, rather plan your trip between April and August (late spring and summer). The monsoon rains are heaviest in July and August. For trekking in the northern parts of the country, June is the best time to travel.

Cyclones are not unusual along the east coast. The risk of cyclones is greatest between the end of October and early December, but they have been known to occur as early as June.