(a) the quantity of coal extracted from the functional coal mines, State-wise, including Tamil Nadu, during the last six years and the details of revenue earned by the Government from these mines;
(b) whether the Government proposes to revive the non-functional mines and if so, the details thereof; and
(c) whether the Directorate General of Mines Safety (DGMS) banned the process of vertical extraction of coal across the country and if so, the details thereof?