1. Ask which Bank and which Branch first. If they hesitate cut the call immediately.
2. If they say the correct branch and bank - please ask for the last 4 digits of your ac number. Your bank will have your ac number always. If they hesitate - cut the call and call your branch manager at the number on your cheque book or passbook and ask why you got such a call.
3. If they provide the last 4 digits of your ac number , ask what they want. If they ask for (a) Date of Birth (b) PAN/AADHAR Number (c) Pin for ATM Card or for Net banking or mobile banking - no matter what they say - the call is a fake. Cut the call. These details will never be asked over the phone. If they want DOB or PAN / AADHAR No - they will ask you to provide KYC Proof to the Branch but will never ask for these details directly.
4. Check for the accent of the caller - it will obviously be an illiterate caller whose english will be quite bad. So if you have an ICICI or HDFC account- you will surely know this cannot be your branch manager. Unfortunately PSU BMS may also talk in a similar way - but there are many indications - ask for the name and he may hesitate, his accent will be pronounced etc.
5.You can soundly ask the person to stop calling you and 99% cases you won't get a call again as he will list your number as dealt and lost.
Stay Alert Stay Safe !