Is it possible to have different stocks with the same stock code on different stock exchanges.
There is no reason that two different exchanges would be prevented from using the same code, although they usually have different conventions. So if you're writing code or spreadsheets that depend on a unique stock code, consider creating a unique code that combines the exchange identifier with the stock code. If this is in a database, use multiple keys in the table; include the exchange ID as one of the key fields.
So the answer is yes, it is possible.