Tamil Nadu government had ordered permanent closure of Vedanta's copper plant.
Tamil Nadu Chief Minister Edappadi K Palaniswami has said the state will challenge the National Green Tribunal order, which set aside government's closure of mining firm Vedanta's Sterlite Copper plant at Tuticorin, in the Supreme Court.
On Saturday, NGT allowed Vedanta's appeal challenging closure of its plant, saying it was "non-sustainable" and "unjustified".
NGT has asked the Tamil Nadu Pollution Control Board (TNPCB) to pass a fresh order for renewal of consent and authorisation to handle hazardous substances. "The Tamil Nadu government will appeal against this order in the Supreme Court," Mr Palaniswami said.
On May 28, Tamil Nadu government had ordered the TNPCB to seal and "permanently" close the mining group's copper plant following violent protests over pollution concerns. Fourteen people were killed and several others were injured in police firing during anti-Sterilte protests on May 22 and 23.
The Supreme Court recently refused to stay a Madras High Court order for a CBI probe against police officials for firing during the protests.