Requirement - If your requirement is, you want to restrict the delivery by pincode. Like you only deliver in pincode 134110 , etc. and you don't want any other pincode person to order something.
Solution - there are many solution available in the market, which I tried and that didn't work for me to be honest. And that too comes for a price.
However I would recommend go to the admin panel -- > shipping -- > shipping providers -- > Configure - Manual (Fixed or By Weight and By Total)--> add your pincode where u provide delivery --> Tick option Limit shipping methods to configured ones
And you are all set. No cost. It is inbuilt functionality.
Still have doubts, email me, I will try to reply everyone.