Step 1: Meaning.
Premium on redemption of debentures = extra liability payable by company over and above face value at redemption.
Step 2: Account type.
It is treated as a liability towards debenture holders → hence classified as a Personal Account.
Step 3: Conclude.
Thus, Premium on Redemption of Debentures A/c is a Personal A/c.
Final Answer:
\[
\boxed{\text{Personal A/c}}
\]