Is there a way to change the data type of the columns in tap-csv? n my csv files, both the columns are of decimal data type but tap-csv reads it as a string. Is there a way to configure the data types in which each column should be read?

yes, https://docs.meltano.com/concepts/plugins#schema-extra

That's the general recommendation and worth trying, but I think meltanolabs/tap-csv doesn't support catalog overrides iirc

Yeah generally for CSV's you transform at the target as everything is a string in a CSV 🤷