Question

Charu said to Mahim, "have you ever been to Banaras?"

narration change

Answer 1

Charu asked Mahim whether he had ever been to Banaras.
l think here you have forgotten to put an appropriate verb after been

Answer 2

Indirect/Reported Speech refers to a dialogue being told to a third person/reporting what happened to a third person.

Example: Gael said,"How is my bag?" (Direct)

                Gael asked how his bag was. (Indirect)

In the above example, when writing in indirect/reported form, the sentence changes according to its tense. Also, modifications regarding certain words like 'this' changes to 'that', 'tomorrow' changes to 'the next day', 'will' changes to 'would', 'can' changes to 'could' and many other words have to be made. Also, if the sentence is contains an interrogation, then 'said' changes to 'asked'. Punctuation marks other than a full stop (.) cannot be used in indirect/reported speech.

Charu said to Mahim,"Have you ever been to Banaras?" (Direct)

Charu asked Mahim if he had ever been to Banaras. (Indirect)