12 Reasons Why India Celebrates Diwali/Deepawali  (Festival Of Lights)

Return of Lord Rama From 14 - years exile, after defeating Ravana.

Return Of Five Pandavas & Draupadi To The Hastinapura.

Victory of Lord Krishna (in avatar of Lord Vishnu) over demon king Narakasura. 

Banishment of King Bali to the underworld by Lord Vishnu.

Release of Guru Hargobind sixth Sikh Guru, from imprisonment.

Celebrated to commemorate the nirvana of Lord Mahavira.

Harvest Festival - marking the end of agricultural season.

Goddess Lakshmi's Birth during Samudra Manthana.

Many Hindu communities celebrate it as New year In Northern India.

It common, it celebrates the victory of light over darkness, good over evil, and knowledge over ignorance.