Can a derivate applicant can apply for F1 - Visa while the Immigrant Visa through Consular Process is pending ?

[smurty]

I got my Green Card (I -551) through an American Software Developemnt Company in July 2007 under EB-3 category under AOS.

I applied for Consular Process for my Wife, daughter and son as derivate applicants to be followed as my family is in India.

The Visa priority date (02 Aug 2002) for my family is yet to be current.

My son has completed under graduation (BS) in India now and got I-20 in Texas State University, San Marcos, US for admission into MS. He got rejected for F1 - Visa.

Is he not eligible to apply for F1 - Visa while his Immigrant Visa is still in process?

Please let me know.