TTML's scrip zoomed 20 per cent to settle at Rs 10.02 - its upper circuit limit on the BSE.
At the NSE, it rallied 19.76 per cent to Rs 10.
Tata Sons has got an approval from the RBI to buy Japanese telecom firm NTT DoCoMo's stake in their struggling joint venture, Tata Teleservices, for Rs 7,250 crore after the central bank changed its rule.
According to sources, the central bank said the "structure of the contract is such that the investor, in any circumstances, if it intends to exit, will receive at least Rs 58.045 or higher per share."
As per RBI norms, the non-resident investor is not guaranteed any assured exit price at the time of making such investment and shall exit at a fair price computed as above at the time of exit.