A floating interest rate on a loan is one that isn't fixed for the entire tenure — instead, it moves up or down periodically in line with changes in the lender's benchmark interest rate, which itself is influenced by broader factors like the RBI's repo rate and overall market conditions. Most home loans in India are offered on a floating-rate basis.
When the benchmark rate rises, your floating-rate EMI (or your loan tenure, depending on how the lender structures the change) typically increases too, and when the benchmark falls, it can decrease. This introduces some uncertainty into your monthly budget compared to a fixed rate, but floating rates have historically tended to work out cheaper over the long run for many borrowers, since lenders often price in a premium for the certainty a fixed rate offers.