For example, there is a flow which gets inputs from user and creates a RateCard(Custom object) record, if it doesn’t exist in the system. Once created, it should show the URL(clickable) of the record created.

This is possible by editing the screen(which is the last step in the flow) and the Display text field there is a little button which shows T(marked in yellow colour in the screenshot below) with what looks like a selection box around it. Type the text you want (View the RateCard record here). Highlight it, and in one of the fields that showed up you can put in the url,something like https://cs5.salesforce.com/{!RateCardIdcreated}

Adding Hyperlink in the Flow

Clickable link
P.S: RateCardIdcreated holds the Id of the RateCard record created.

Please let me know your comments.