The main hindu festivals of India are Holi, Deepawali, Dussehera and Rakshabandhan.
The two prime forms of Dussehera is Dussehera and Durgapuja. Bengal worships Mother Goddess Durga and celebrates her slaying demon Mahishasur. The rest of the India celebrates navratri with ramleela or dandia dance. They celebrate this day as the day when Sriramchandra slayed demon Ravana. The metros become semi carnival grounds during these days, especially Kolkata. If you are afraid of crowd, better skip this season, and if you want to enjoy the warmth, celebrating mood of a community you should come during this season.
It’s quite intriguing to study how same culture gets locally tinged in a versatile country, like India.
I personally believe they must have had the same origin because the dates are same as per Hindu calendar but down the long, long road of millenniums they got regionalized.
Gujarat etc celebrate Navrartri, they worship another form of Madurga their celebration’s specialty is dandia dances, Uttar Pradesh etc celebrate it as Sriramchandra’s victory over Ravana, and my humble state celebrates it as Madurga’s slaying Mahishasura a demon king.
In gist they all celebrate victory of good over evil.