The market on Wednesday opened firm supported by banks, auto, infra and pharma stocks.
The Sensex traded up 131.18 points or 0.5 percent at 26526.89, and the Nifty gained 38.35 points or 0.5 percent at 8147.20.
Shares such as Adani Ports, Bhari Airtel, SBI, NTPC and BHEL were among the top gainers while ICICI Bnak, Dr Reddy's and TCS were down in the Sensex.
The Indian rupee opened flat at 67.25 per dollar against previous close of 67.26. The Yuan slipped to its weakest level since early February in offshore trading after MSCI Inc. denied local equities entry into their indexes.
Market experts believe that the trend in the rupee can remain under pressure due to global events. If Indian equity market trades positively on the back of GST news then the rupee may get some support near 67.50/dollar levels.
Global markets are jittery as investors are keenly waiting for the Federal Reserve decision on rates and Bank of Japan policy meeting outcome while upcoming vote on whether the UK will remain in the European Union looms large.
Also, the crude prices declined led by Brexit concerns, which overshadowed signs of a return to health for crude prices. International energy agency, said the oil market is essentially balanced after two years of surpluses. Gold price is near 6-week high on expectations the Federal Reserve won't raise rates today.