Why Indian ATM showing currency conversion option for withdrawal?

Hi, we have tried cash withdrawal with two Niyo SBM cards in SBI ATM today. All locks are open and pin set.

The first card timed out. The second card showed the option of currency conversion by VISA/Mastercard.

Why is it required when we are withdrawing in INR ? There is no conversion involved. Should we go ahead with this option everytime? Will there be any charges ?

We couldn’t proceed further as we did not know if we would be charged.

Also when we tried the first card again, the transaction got cancelled.