Section 7(3)(c) in The Forest (Conservation) Rules, 2003
(c)The Regional Office shall however seek prior clearance of the Ministry of Environment and Forests whenever the proposal involves clear-felling of forest land having crown density above forty per cent irrespective of the area involved, or clear-felling of forest area of size more than twenty hectares in the plains and ten hectares in the hilly region, irrespective of density.