Rohingyas have already received ISO (International Standard Organization) recognition for their language that is Rohingya/Rohingya language. SIL.ORG has already released, as the final approval as of 18 July 2007, the code  (RHG) as the Language code for Rohingya as being the distinct language on earth.  Previously Rohingya language was placed under CIT (Chittagonian) but now CIT has been made retired. They have separated the two, Ctg for Chittagonian and Rhg for Rohingya.  
You can visit SIL.ORG website or click links below.

http://www.sil.org/iso639-3/cr_files/2006-048_ctg.pdf