IFSC is an 11-character alphanumeric code used for electronic transfers (NEFT, RTGS, IMPS). MICR is a 9-digit numeric code printed on cheques for cheque clearing. A branch usually has both, but they are used for different payment channels.
Which one do I need?
Sending money online to an account number → IFSC.
Filling a cheque or a mandate form that asks for MICR → MICR.
Setting up salary credit → usually account number + IFSC.
FAQ
Questions
Can I convert MICR to IFSC?
Yes. Search the MICR code here; the result shows the branch and its IFSC.