If you are getting Google Adsense check this month (may 2009) or later, you can not track status of check through reference number at BlueDart website. Earlier when Adsence check was coming through DHL courier, status or location of check was traceable through shippers reference number (payment number). After few day (5-6 days) of dispatch, DHL Airway bill number used to get appear in payment details.
Once DHL airwaybill number appeared, the check was traceable from Blue Dart also, using same airwaybill number. Blue Dart and DHL are business partner in India.
Now Google has decided to send the check to all publishers in India through Blue Dart only, you can track Adsense check only if Airwaybill number will appear in payment details.
As per email, it will be available before 15th of month. Without airwaybill number there is no way to track. Till now reference number (payment number) is not working in Blue Dart tracking tool.
If Blue dart will not be able to reach you, they will sure call you, so make your contact number updated.