Identifying the single "highest return" mutual fund in India varies across dynamic market cycles, economic conditions, and evaluation time horizons. Historically, small-cap equity funds (such as Nippon India Small Cap Fund and Quant Small Cap Fund) alongside focused sector or mid-cap funds have generated exceptional long-term compound annual growth rates (CAGR) exceeding 19% to 24% over multi-year periods, though past performance never guarantees future investment returns.