This post tells you how you can open a fixed deposit or FD account online in SBI using Internet banking. Basically you need to have Internet Banking enabled on your SBI savings account to open a fixed deposit online.
If you don’t have Internet Banking enabled, just go to your SBI branch and ask them for an ‘Online SBI Registration Form’. Fill the form and they will give an envelope containing your Username and Password.
The interest rate given on savings account in SBI is just 2.70% p.a. which can’t beat the rate of inflation. It means customer’s money is depreciating in a savings account.