I have forgotten my South Indian Bank account number and cannot find where I stored it on my hard drive. What is the procedure I need to undergo to reconnect with my account? What information will they ask for to do this?
The easiest way is most likely to simply visit the bank in person. Bring proof of your identity (passport, driver's license, national photo ID card, or whatever else happens to be most viable in your particular case), walk up to the counter and simply tell them that you forgot your account number and need them to tell you what it is.
With a very high degree of likelihood they will be able to help you out right then and there, and if they can't because of some regulation (government-imposed or company-specific), then they will tell you exactly what more they need from you.
If you want to, you certainly can call the bank and ask what documentation they will need before going to the branch office yourself, and there is always the possibility that you can call them and ask them to send you some type of customer summary which will include this information, but they almost certainly won't be able to simply give you the account number over the phone because you most likely don't have any way to prove to them over the phone that you are who you claim to be with regards to your account. So likely the best you can hope to get out of a phone call is to be told what sort of documentation you need to bring with you when you visit the branch office, or if you are lucky that they will agree to physically mail the information to you.
Try the contact form here, but I'm not sure if it will work without the account number:http://www.southindianbank.com/Forms/Enquiry.aspx