Can I use my HDFC visa debit card to withdraw CHF from ATM's in zurich?

The ATM that you are going to use has to be attached to any network as any of the networks that your issuing bank is a member of. At least in the U.S., ATMs generally show what networks they are attached to. If the ATM shows the VISA logo you should be okay.

If you do see a network logo that's on your card, like STAR, or SWITCH, or some others, then you're also okay. If you're still not sure, check what logos are on your card, some banks and credit unions are on sometimes 2, 3 or more networks. Next, go to the website of any of the ATM networks your card is on and check for banks in Zurich on that network and they’ll probably even give you addresses.

I’m not sure what bank HDFC is or what country your card was issued from. If it’s a U.S. bank you should be okay. Some countries have currency controls and do not allow a credit or debit card to be used outside the issuing country to prevent money from being sent out of the country.

As far as withdrawing Swiss Francs, that’s what you’re going to get if that’s the local currency. I once used my BB&T (a U.S. east coast bank) debit card at a bank in Ontario. The currency issued was Canadian dollars, and my card was charged the appropriate fee based on the conversion then for CAN to USD plus the service charge (3% I think).

This was over 5 years ago so then a CAN$ was about 65c, so for each $20 CAN I would roughly be charged $13.50 USD plus another 40c or so. Not sure if they charged external terminal fees. More or less the same thing will apply in your case if the country of issue allows international transfers and your card is on a network of that ATM.

They will issue you the local currency there, and charge you at the current interbank rate for a currency conversion, plus any international fees and terminal fees.