Section 150(3) in Gauhati Municipal Corporation Act, 1971
(3)All plant and machinery contained or situated in or upon any land or building and belonging to any of the classes specified from time to time by public notice by the Commissioner under bye-laws made in this behalf shall be deemed to form part of such land or building for the purpose of determining the rateable value thereof under sub-section (1) bus save as aforesaid no account shall be taken of the value of any plant or machinery contained or situated in or upon any such land or building:Provided that where the Corporation so resolves, the annual value in case of owner occupied building and land shall for the purpose of assessment of property taxes be deemed to be 25 per cent less than the annual value otherwise determined under this section.