The scrip of the country's largest software exporter plunged 8.5 per cent to Rs 2,451 on the BSE.
The bellwether stock was the top loser among the 30 Sensex scrips.
At the NSE, the stock tanked 8.51 per cent to Rs 2,450.
"While the dollar revenue was much higher-than-expected, net profit came in lower-than-expected, on back of lower-than-expected EBITDA margins," said Sarabjit Kour Nangra, VP Research - IT, Angel Broking.
TCS had yesterday posted 13.2 per cent jump in September quarter net profit at Rs 5,244 crore and remained "bullish" about the next fiscal.
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In the year-ago period, its net profit stood at Rs 4,653.9 crore.
"TCS reported Q2FY15 results below consensus expectation on all counts," brokerage firm Prabhudas Lilladher said in a report.
Unveiling the earnings figure, TCS also announced the merger of its subsidiary CMC with itself. The merger ratio is 1:1.26 or 79 TCS shares for 100 CMC shares. TCS had bought CMC from the government in the 1990s through a divestment process.
TCS revenue jumped 13.5 per cent to Rs 23,816 crore in the second quarter ended September 30 as per the Indian GAAP system of accounting.