I’m happy to give a 10% tip, the problem will be in Mumbai as I understand we can’t buy Indian currency outside of India. I imagine we will get off the plane, go through the usual entry formalities and be taken straight to the transfer car without being able to get any local currency. Could I give a tip in another major currency (I’m thinking US dollars) or would that cause the recipient more trouble than its worth? I’d like to do the right thing if I can.