Mumbai Feb 18 PTI The rupee opened on a flat note against the US dollar in opening trade on Friday as caution set in amid worries about escalating Russia-Ukraine tensions At the interbank foreign exchange the rupee witnessed range-bound trade as it opened at 7503 against the US dollar saw an early high of 7502 and a low of 7505 against its previous close of 7506 Meanwhile the dollar index which gauges the greenbacks strength against a basket of six currencies rose 001 per cent to 9580 Meanwhile global oil benchmark Brent crude futures fell by 054 per cent to USD 9247 per barrel Crude oil prices were weak this Friday morning and could lend support However possible escalation of tension in Eastern Europe could cap appreciation bias said Sriram Iyer Senior Research Analyst at Reliance Securities Markets could remain range-bound ahead of the weekly expiry Iyer said On the domestic equity market front the 30-share Sensex was trading 1634 points or 003 per cent higher at 5790835 while the broader NSE Nifty slipped 630 points or 004 per cent to 1729830 Foreign institutional investors remained net sellers in the capital market on Thursday as they offloaded shares worth Rs 124210 crore as per stock exchange data PTI DRR MKJ