Section 177(1)(a) in The Maharashtra Municipal Councils, Nagar Panchayats And Industrial Townships Act, 1965
(a)(i)if the projecting part thereof is any structure external to the main building, then at any time; or(ii)if the projecting part is not an external structure as aforesaid, then whenever the greater portion of such building or whenever any material portion of such projecting part has been taken down or burned down or has fallen down, require by written notice either than the part or some portion of the part projecting beyond the said regular line shall be removed or that such building when rebuilt shall be set back to or towards the said regular line;