The first four characters (ANDB) represents that it belongs to Andhra Bank. The fifth character (0) is reserved for future use. The last 6 characters (001668) represents that it belongs to Model Town Extn Ludhina branch in district Ludhiana of Punjab.
IFSC code (ANDB0001668) can be found on the front page of the account holder's passbook or in cheque leaf. You can also verify the same by contacting bank authority of Andhra Bank since data here could be outdated.
Model Town Extn Ludhina branch of Andhra Bank is in Punjab state of India.
38A, MODEL TOWN EXTENSION, LUDHIANA, PUNJAB-141002