You can't do this in a For Next loop in the report. Based on the query you posted, it looks like you're using Oracle. I'm also going to assume that this query is a Command in the report.
To use a multi-select parameter in a Command, you'll do something like this:
and cia.equipment_id in {?Equipment ID}
If you need to make this parameter dynamic, see this blog post: https://blogs.sap.com/2015/04/01/best-practices-when-using-commands-with-crystal-reports/
-Dell