The companies wanted to increase tariff as they said a change in Indonesian laws on coal export prices in 2010 had raised costs - both source raw coal from Indonesia.
The Central Electricity Regulatory Authority or CERC had allowed the companies to charge more in December, agreeing that the change in Indonesian laws was outside their control.
State power companies challenged the decision in the Supreme Court.
The two companies produce 8620 MW of power in the five states.
The shares of Tata Power fell about four per cent and that of Adani Power slumped 16 per cent in afternoon trade on the Bombay Stock Exchange.