Section 112(5) in The Coal Mines Regulations, 2017
(5)During the extraction of pillars, no splitting or reduction of pillars or heightening of galleries shall be effected for a distance greater than the length of two pillars ahead of the pillar that is being extracted or reduced:Provided that where pillar extraction is about to begin in a district, such splitting or reduction of pillars or the heightening of galleries shall be restricted to a maximum of four pillars.
