The 30-share index ended the day at 27,981, down 21.41 points, while broad-based 50-share index quoted 8,622, down 13.65 points at close.
Analysts however said the GST Bill's enactment was unlikely to spur any major rally given indexes were seen already reflecting a positive outcome.
The broader NSE Nifty hit its highest since April 2015 on Monday.
"A rally in the short-term might not sustain for too long," said Neeraj Dewan, director at Quantum Securities.
"We can also expect some amount of profit-booking happening as the Bill progresses."
Maruti Suzuki stock was the top gainer on both the benchmark indices and added over 2 per cent after the auto major posted robust sales growth in the month of July.
Auto makers were among the leading gainers after companies reported robust sales in July. The S&P BSE Auto Index rose as much as 1.1 per cent to a record high.
Maruti Suzuki India rose as much as 2.8 per cent to a record high after its July sales went up by 12.7 per cent.
The car maker has hiked prices of select models effective August 1.
Sun Pharmaceutical Industries gained as much as 1.4 per cent after US health regulators approved the drugmaker's generic version of diabetes drug, Glumetza.
Shares of software services provider Tech Mahindra rose as much as 4 per cent on strong June-quarter results.
Shares of InterGlobe Aviation, which owns budget airline IndiGo, fell as much as 6.9 per cent to their lowest since July 5 as Q1 profit fell, hurt by "competitive fare pressures."