Shares edged up in thin trade on Thursday as Britons began voting on a referendum on whether Britain should remain a part of the European Union.
Opinion polls taken before the vote indicated the outcome is far too close to forecast, with results expected to be out on Friday in India.
Most polls put the "Leave" and "Remain" camps neck-and-neck at the end of the campaign that was dominated by immigration and the economy, and shaken by the murder of a pro-EU MP, though late on Wednesday two showed a swing to "Remain".
Shares of companies with considerable exposure to Europe traded mixed, with Tata Motors Ltd and Bharat Forge Ltd recovering some ground after Wednesday's losses and software services exporters trading lower.
Investors just want the Brexit vote to pass, as they have hedged their positions substantially, said Harjit Singh, deputy research head of Aldmondz Global Securities Ltd.
"There is an appetite at the lower level should markets react," he said.
The Sensex ended 236.57 points or 0.88 per cent higher at 27,002.22. The NSE Nifty gained 66.75 points or 0.81 per cent at 8,270.45.
Tata Motors gained 3.23 per cent, recovering from a fall of 3.47 percent in the previous session after Reuters reported unit Jaguar Land Rover's annual profit could be cut by 1 billion pounds if Britain left the 28-member trading bloc.
Bharat Forge Ltd rose 1.93 per cent to Rs 752, also recovering from Wednesday's decline.
But software services exporters fell, with TCS down 0.82 per cent at Rs 2,643.75 and Tech Mahindra falling 0.37 per cent to Rs 530.80.
Healthcare stocks led the gains, with Natco Pharma Ltd rising as much as 8.1 per cent after CNBC-TV18 tweeted that the company won US FDA approval for ulcer drug glycopyrrolate. The stock finished higher by 4.40 per cent at Rs 552.20.
Sun Pharmaceutical Industries Ltd rose as much as 2.4 per cent ahead of the company's board meeting to consider a share buyback plan. The stock finished 1.60 per cent higher at Rs 751.90.
YES Bank gained 3.14 per cent to Rs 1,112.75. Bank of Baroda rose 2.55 per cent to Rs 152.90. PNB climbed 2.37 per cent to Rs 99.30. SBI added 2.30 per cent to Rs 217.80.