Tata Teleservices share price: The counter's 14-day relative strength index (RSI) came at 83.15. A level below 30 is defined as oversold while a value above 70 is considered overbought. The company's stock has a negative price-to-earnings (P/E) ratio of 13.39. It has a negative price-to-book (P/B) value of 0.80.