Mumbai, June 27 -- The Indian rupee extends winning streak on Friday amid sustained weakness in greenback overseas. The US Dollar Index (DXY), an index of the value of the US Dollar (USD) measured against a basket of six world currencies, sinks to its lowest level in three and a half years under 97 mark following ceasefire between Israel and Iran. INR opened at Rs 85.50 per dollar and climbed to a high of 85.46 so far during the day. Yesterday, rupee rose 34 paise to 85.75 (provisional) against the US dollar on the back of a sharp drop in the greenback and a strong show in the domestic equity markets amid rise in risk appetite. The benchmark 30-share BSE Sensex surged 1,000.36 points, or 1.21 percent, to 83,755.87 while the broader NSE Ni...