Besides, Rohit Sharma, Vijay (Test reserve) and Raina (current Test starter), famous for IPL/CLT20 exploits, have also done well over a period of time in first-class and list-A cricket, so it gets down to who adds more value.
We'd prefer a more complete picture, and more complete players making it to the team. Scoring runs against top international bowlers is more important than dominating no-name-no-face domestic extras, so let's not deride the IPL too much.
I'm out of touch with the TN domestic scene, but Vijay may have played more games for clubs than Mukund, and the selectors plumped for experience, as against kids playing in the frontline for Saurashtra and Maharashtra. Besides, someone named Arun Karthik is tippedas a better batsman, even though he doesn't make the XI too often. TN is one of the better oganised teams in India.