The company had reported a net profit of Rs 762.27 crore in the July-September quarter a year ago.
Its revenue, however, increased by 7.2 per cent to Rs 9,300.23 crore in the quarter under review from Rs 8,675.37 crore in the year-ago period.
Shares of Idea today closed at Rs 77 a unit, down 3.75 per cent from the previous close on the BSE.