What is Cost Inflation Index, set at 363 for FY25 by I-T Dept?

Income Tax Department has set Cost Inflation Index (CII) for FY25 at 363. CII comes into play in sale of long-term asset and calculation of capital gains, difference between the cost of acquisition and sale. The larger the capital gain, the larger the tax it'll attract, which CII reduces by increasing cost of acquisition by indexing it for inflation.