documents to chennai consulate for visa
For stamping of visa at a consulate subsequent to your H-1B extension:
you need to carry I-129 application, H-supplement, duly certified lca, I-129W, letter from company requesting the consulate to issue you a visa, your most recent paystubs (atleast 2 to 3), a picture for stamping, your passport and the current fee. These documents should do.