Comment by gilbetron

Illegal in India maybe. In the US: "In the United States, Part 15 of the U.S. Federal Communications Commission rules specifies that no license is needed if range of the transmitter does not exceed 200 feet (61 meters), although the Part 15 rules specify that the field strength should not exceed 250 µV/m (48db) at 3 meters"

I haven't found the exact law in India, but looks like maybe it's legal for personal usage of FM provided power of transmitter is under 500 mW?