“May I know your good name” is a typically Indian way of honouring the other person (who is previously unknown) by asking their name using an adjective like sweet, good, beautiful, et cetera — and of course there won’t ever be any bad or sour name (unless we feel it such) to be asked.
If the aforementioned way of asking someone’s name is incorrect or unrecognizable, then how could I make it sound more polite and amicable without negotiating the basic principles of English?