Tax incentives allowed 15,080 profit-making Indian companies to have effective tax rates of zero, and in some cases less than zero, in 2015-16, according to an IndiaSpend analysis of the latest available national tax data or more specifically a government analysis called the Revenue Impact of Tax Incentives under the Central Tax System.
The central government introduced minimum alternate tax (MAT) in the late 1980s to tackle this anomaly, but even MAT has exemptions that appear to have negated its original intent partially: 52,911 companies made profits in 2014-15 and paid no tax, IndiaSpend reported in March 2016.
— source indiaspend.com by Rohit Parakh