Sensex, Nifty hit new highs but sentiment cautious

India's equity indices, including Nifty and Sensex, reached new highs with modest gains on Monday. Nifty was up 0.2% closing at 25,278, and Sensex increased by 194 points to 82,559. However, mid- and small-cap indices saw declines. Upcoming US Federal Reserve decisions are anticipated to impact the market further.