A bank will usually lend between 75-80% of the agreement value, and the borrower has to provide the rest from personal resources. To clarify - while the RBI stipulates a ceiling of 75%, some banks are willing to include the stamp duty and registration charges within the purview of the loan, which technically makes the loaned amount 80% of the agreement value.
The lending rate attached to the home loan also changes from time to time, depending on how the economy is faring and how much liquidity exists on the market.