Could anyone please tell me how to achieve this?

You want this format written where? In a richtext field? An email subject / body? An inlinehtml field? If it's a string you can probably you can probably use string.replace with whatever format you need the carriage return to be if it's the only text. If it's an array you can use Array.join() in a similar fashion.

i have a result as CSV format, i need to change this into a row look

In SuiteQL: LISTAGG({field}, ',') should concat a field, you'll need to group the results etc

@Sam L sorry i dont get it.

What is the field and what table?

select custrecord_vendor_subsidiary_autoselecti from subsidiary; This is the query

If the field is a multi-select, look for the mapping-table in the records catalog and use that to get individual lines instead of an automatically concat:ed text.