Unable to add rows dynamically using records

That's normal since you are saving multiple files in the same variable (ri!upload).

Here is an example that might help understand

a!localVariables(
  local!pdfs,
  a!gridLayout(
    headerCells: { a!gridLayoutHeaderCell(label: "File") },
    rows: a!forEach(
      items: local!pdfs,
      expression: a!gridRowLayout(
        contents: {
          a!fileUploadField(
            value: local!pdfs[fv!index].fileId,
            saveInto: local!pdfs[fv!index].fileId,
            maxSelections: 1
          )
        }
      )
    ),
    addRowLink: a!dynamicLink(
      label: "Add new row",
      saveInto: {
        a!save(
          local!pdfs,
          append(local!pdfs, a!map(fileId: null))
        )
      }
    )
  )
)

You are trying to append the ri!  variable to a local variable . Can you specify what is the data passed to ri! is it the record structure .

Instead you can use the record type in the local variable and append it to the local variable local!pdf. 

data passed to ri! is the record . 

I have tried doing it but its not working , i have called a record in local variable and tried to append with local!pdf.

ok, for local!pdf you need to give like an array set. 

Try local!pdf: {} it will work.

In the ri!record for the record give the  empty data like

recordType!ABC(

id:null(),

createdby:null()

)

give all the required fields to capture in the Grid

No , I am able to add but when i add 2 documents for one type and when i try adding a new document its taking the document which i uploaded for the previous ones.

You mean test for ri!ecord give the data which are required?

a!fileUploadField(
value: local!pdfs[fv!index].fileId,
saveInto: local!pdfs[fv!index].fileId,

In the value it is in loop use fv!item[record field to store]