error using INDEX MATCH with @row

I'm trying to parse a column from one sheet to another.

The formula I'm using is =INDEX({sheet with column Range 1}, MATCH(client@row, {sheet with column Range 1}),1)

The end of the formula is 1 as the column number is 1.

I'm getting an UNPRASSABLE error.

Cans somebody please advise.

Thank you.