From the top-10 pack, only RIL, HDFC and SBI witnessed gains in their market valuation for the week ended Friday.
The valuation of TCS tumbled Rs 26,900.6 crore to Rs 6,22,401.90 crore, making it the top loser among the pack.
The m-cap of Reliance Industries Ltd zoomed Rs 28,494.36 crore to Rs 8,57,303.03 crore, the most among the frontline entities.
The Tata Consultancy Services scrip declined 3.76 per cent to Rs 1,929 on the BSE.
TCS will now have 8.2 pc constant currency dollar growth in the full year which will be way below its double-digit growth.
IT major Infosys has been ranked third in the list of World's Best Regarded Companies, along with global payments technology company Visa.
Reliance Industries Ltd (RIL) had on Monday raced past TCS to become the country's most-valued firm by market valuation.
Reliance Industries Ltd (RIL) was the only firm among the top 10 companies to post a gain in its market valuation.
TCS on Tuesday reported 10.8 pc growth in consolidated net profit to Rs 8,131 crore for the quarter ended June 30.
The scrip declined 2.05 per cent to close at Rs 2,131.45 on the BSE. During the day, it fell by 3.95 per cent to Rs 2,090.