Section 77(4) in The Indian Electricity Rules, 1956
(4)For extra-high voltage lines the clearance above ground shall not be less than 5.2 metres plus 0.3 metre for every 33,000 volts or part thereof by which the voltage of the line exceeds 33,000 volts:Provided that the minimum clearance along or across any street shall not be less than 6.1 metres.
