if ITC can be bought with multiple currency how reserve in BNT will be calculated
It doesnt matter what currency it is bought with, because that user gets the same amount of ITC that they would have if they first converted their BTC to ETH first. So the total value exchanged is the same either way. Its just more convenient for the user. The reserve in BNT is based on the number of ITC tokens, so all that matters is how many ITC there are, not what currency was originally used to buy them.
Thanks for your answer I asked this question because bnt is only bought by ethereum.