[LitlBuck]

Originally Posted by ScriptOhio

Here's a 1994 article, it still may apply.

The resolution was approved this week by the delegates at the National Collegiate Athletic Association convention in San Antonio. An underclassman who declares himself eligible for the draft will now be allowed to change his mind should he be dissatisfied with the outcome. The player will have until 30 days after the draft to reverse his decision, and may only exercise the option once during his college career.

Entire article: BASKETBALL; College Draft Resolution Has the N.B.A. Worried - New York Times

I do not think that is the rule anymore. I think once you are drafted you can not come back to school. You lose your eligibility.