linking with interface

One city Name and area name mean? Combination of both should be unique?

i just want one row of state and area name so that means i just want to fetch only the detail with is at first index in integration object

Then you can use index function. For example: index(local!result,1,{}). It will return the data at first index,

I want state and area name from integration object which is at index 1. So in interface i have used read 

only grid in that i use coloum and in display value i have done fv!row.name so it is give me all name i just want- 

first name which is at index one how can i do this plz help me 

a!localVariables(
  local!result: index(
    a!flatten(
      index(
        a!fromJson(
          index(
            index(
              rule!INT_currencyConverter(110001),
              "result",
              {}
            ),
            "body",
            {}
          )
        ),
        "PostOffice",
        {}
      )
    ),
    1,
    {}
  ),
  a!gridField(
    data: local!result,
    columns: {
      a!gridColumn(label: "Name", value: fv!row.State),
      a!gridColumn(label: "Area", value: fv!row.Name)
    }
  )
)

Let me rephrase your question.

You are getting multiple result from the integration for example 5 rows. Now, you want to show only 1 rows which is at index 1 into the grid instead of all the 5 rows. Correct? if yes, then into the data configuration on your gridField use index(local!result, 1, {}).