honda city - get tax certificate chennai -?

hi i bought a honda city car last year 2012 from a dealer in chennai. not sure if the dealer had paid the one time lifetime road tax or not. how do i know whether it has been paid or not can i request for a copy of the certificate with the dealer can a traffic cop fine/ask bribe if i dont have a road tax certificate/ am an NRI and just moved back to india - so new to the procedure