Saint-Gobain India is planning to invest Rs 3,400 crore in Tamil Nadu across various businesses as part of its commitment to invest Rs 8,000 crore in the state over the next 4-5 years. The investment will include green and brownfield projects in manufacturing sectors such as glass wool, gypsum plasterboard, plaster, acoustic ceiling, float glass, solar glass, adhesives, sealants, mortars, and ceramics.