Can I know the reason for sudden change of names of Madras,Bangalore,Calcutta to Chennai,Bengaluru,Kolkatta.?

cos they hate the British. and it was the British who named these places for easy pronunciation, now they are going back to the old names. just like some of the roads in India have changed names,, makes no rhyme or reason to me, people from all over the world know Bombay as Bombay, not mamba. madras curry is a UK favourite, Chennai doesn't have the same togetherness. stop being so silly. you politicians. India is steeped in history. you cannot eradicate it, by changing a name.