yeah, i agree with Prince there..."No meat,no alcohol" is recommended - dont think it's a rule though...but I dont know of any Hindu festival that disallows sex.
Different parts of India celebrate Navarathri in different ways. Durga pooja (Worship of the mother godess) is a Bengali specialty. Tamilians put their traditional dolls on display (they arrange it in steps) and women invite their other women friends over to exchange gifts and snacks. Garba and Dandiya are a Gujarati tradition- the dances go on all night...colorful and fun
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And Mysore city (near Bangalore) gets its name from the Demon Mahishasura, who was killed by Godess Chamundi (a manifestation of Godess Durga) after 9 days of fierce fighting. She killed him on the 10th day (Vijayadashami) - the last day of the Navarathri celebrations. Each region has its own story...these are just the few i know of