N.K.Singh is the chairman of the FRBM review committee. It was set up in May 2016 by the Government of India to review the FRBM Act. The fiscal deficit target was changed to 3.2% by former Finance Minister Arun Jaitley in his budget speech of 2017. This change was done referring to the N.K.Singh headed FRBM Review Committee report. The committee had recommended a fiscal deficit target of 2.5% by 2023. You can read about the Fiscal Responsibility & Budget Management (FRBM) Act in the given link.