He doesn't have any specific supplier, he has got his bats from SS, SG, RNS, BAS, BDM, CA and many other suppliers in India/Pakistan. He just has a fixed profile and he gets his bats made by guys and whatever he likes, he keeps and rest of them are sold at various places. I have also heard that he has started using semi-oval and tapered handle (thicker at the bottom than thinner at the top) though he is a very wristy player.
All the professional Indian players including Sachin and Dhoni....... have/had fixed profiles and they just got those profile bats made by different suppliers (though BAS was Sachin's favorite towards the later part of his career). There are only a few cricketers who have stuck to one supplier (e.g. I have heard that Rahane buys his bats only from PR - a small supplier from Meerut or Sehwag and Dravid mostly used SG in later parts of their careers).