Yes, you can revoke the POA by instructing your broker and following the required steps. Mostly by sending the POA revocation form.
Update: @Neha_Raghuraman All the new Zerodha accounts are non-POA accounts. You will soon be able to revoke POA online and move to the non-POA or eDIS route.
All the new accounts are Non-POA accounts so eDis is route is already available for them. Revoking POA online is the only process to be updated. No ETA but soon
@ShubhS9 I am contemplating revocation of POA. Are there any consequences I need to be careful about besides the requisition of TPIN to sell holdings??