i don't remember my pnb atm pin what should i do ???

Call 1800 180 2222 (Toll Free) for ATM Debit card related queries. Generally they can reset it during phone call if you provide them right credentials.In case you do not get the Call Centre no, contact helpdesk no of ATM Switch at 011 -23765143, 011 - 23323672.

Other way is to ask for reissue of PIN by visiting branch, they will send it through mail as you first time received it.