Modern Saree & Matching Centre in Green Park is a fairly missable little sari store—one in a wall-to-wall explosion of stores on the strip of Green Park market. You'll find it sandwiched casually between a grocer or two, with a super sweet uncle seated behind the counter at the doorway. When you wander in further, you'll find the small store packed to the rafters with saris and dress materials in a variety of hues and materials.
Head here if you want to pick up fabric to get an outfit stitched without having to go through the chaos of a fabric market, or if you want to get a sari for yourself or as a gift for somebody else.
Honestly, I saw a lot more chiffon, georgette and nylon than I saw cottons and linens, but if your taste runs to that, you will not be disappointed. Also, expect a LOT of floral prints in their mix.