In a relief to coal mine owners in Meghalaya, the National Green Tribunal on Tuesday extended the time for payment of royalty of already extracted coal in the State by a month after the State Government said heavy rain had hampered the transport of coal. A Bench headed by NGT Chairperson Justice Swatanter Kumar also directed the Ministry of Coal and Ministry of Environment and Forests (MoEF) to examine the draft guidelines on mining submitted by Meghalaya Government expeditiously.