There are no direct flights from India to Chiang Mai. However, there are plenty of flights that connect through Bangkok, which is only a few hours away.
The nearest airport to Chiang Mai is the Chiang Mai International Airport. There are frequent flights from Bangkok, Singapore, Kuala Lumpur, Hong Kong, and other major cities in Asia.
The best way to reach Chiang Mai by road is to take a bus from Bangkok. There are also buses from other major cities in Thailand.
There is no railway station in Chiang Mai. The closest railway stations are in Lampang and Chiang Rai.
There are three bus terminals in Chiang Mai: Arcade Bus Terminal, Chang Phueak Bus Terminal, and the new Mae Kho Bus Terminal. The Arcade Bus Terminal is the most centrally located and is the main terminal for buses travelling to and from Bangkok.
The best way to get around Chiang Mai is by songthaew (a pick-up truck with two benches in the back). You can hail them from the side of the road, or find a fixed route and stop anywhere along the way.