I will complete my master degree by this end of fed 2012 but unfortunately I only have visa till 15th march.. I may not be able to collect all the document required for TR apply before 15th march.. as my visa is expiring on this date.. can I apply TR after this date?or is there any other alternative?please advise me...

Here is a Federal Government site which contains all the information you need: What the Visa Expiration Date Means (http://travel.state.gov/visa/temp/info/info_1298.html)