Under RBI's law, an individual is entitled to a single free credit report every 12 months from each credit bureau. It means in a year you can avail four free reports from four different bureaus.
Your credit scores, which help lenders, decide whether to extend credit to you and at what interest rate, are calculated from data in your credit report. Those should be checked at least once a year unless you plan to apply for credit. If you are working to build or rebuild credit, or for any other reasons an individual should peek the credit report about once a month so that you can monitor your scores.