He chose to study Financial Administration at Harvard Kennedy school in 1987 while he held the position of District Collector and Magistrate in the state of Kerala, India.

[13][14] He is the chairman of United Nations Panel of External Auditors [15] and member of the Governing Board of the International Organization of Supreme Audit Institutions (INTOSAI).

[16] The panel headed by Vinod Rai discussed the major business transformations currently under way in the United Nations with Secretary-General Ban Ki-moon.

[17] Vinod Rai recommended that all private-public partnerships (PPPs), "Panchayti Raj Institutions" and societies benefiting from government funds should come within the ambit of the CAG.

[18] He is widely credited for the report on issue of Licences and Allocation of 2G Spectrum by United Progressive Alliance government which resulted in a huge controversy in India.

[19] In a chargesheet filed on 2 April 2011 by the investigating agency Central Bureau of Investigation (CBI), the agency pegged the loss at ₹309,845.5 million (US$3.6 billion)[20] On 2 February 2012 the Supreme Court of India on a public interest litigation (PIL) declared allotment of spectrum as "unconstitutional and arbitrary" and quashed all the 122 licenses issued in 2008 during tenure of A. Raja (then minister for communications & IT in United Progressive Alliance) the main accused.

[21] The court further said that A. Raja "wanted to favour some companies at the cost of the public exchequer" and "virtually gifted away important national asset".

[citation needed] The main criticism to the report now emerging is that the CAG exceeded its constitutional mandate as it attempted in a sense to change the policy of the Government of India which at that point was to promote telecom growth and not revenue maximisation by arguing that spectrum could only be sold by auction and creating figures for Presumtive losses around it.

However, the Honble Supreme Court Of India in the Presidential Reference (2012) has upheld the right of the Government to frame policy and said "The norm of 'common good' has to be understood and appreciated in a holistic manner.

[citation needed] In 2014, Rai named Sanjay Nirupam as one of the MPs who pressured him to leave former prime minister Dr. Manmohan Singh out of the report.

[23] In a written affidavit Rai said: “That I have realised that in answer to questions posed to me by the interviewers, I had inadvertently and wrongly mentioned the name of Sanjay Nirupam as one of the MPs who pressurised me to keep the then Prime Minister Manmohan Singh’s name out of the CAG report on 2G spectrum allocation during the meetings in the PAC or the sidelines of JPC.”[24] Based on the recommendations by amicus curiae-senior advocate Gopal Subramaniam who was investigating the issues of financial irregularities and mismanagement in the Padmanabhaswamy Temple, the Supreme Court of India issued an interim order on 24 April 2014 stating that Mr Vinod Rai will supervise special audit of property of temple.

[27] On 21 December 2017, a Special CBI Court acquitted all the persons accused in the 2G scam, a case set in motion by Vinod Rai.

The Special Judge OP Saini stated in his judgement: "There is no evidence on the record produced before the Court indicating any criminality in the acts allegedly committed by the accused persons.” He added that “the chargesheet of the instant case is based mainly on misreading, selective reading, non-reading and out of context reading of the official record” and that "the chargesheet is based on some oral statements made by the witnesses during investigation, which the witnesses have not owned up in the witness box.”[28] In October 2021, after Vinod Rai unconditionally apologized to Sanjay Nirupam, the Indian National Congress's leader Adhir Ranjan Chaudhary said, "Vinod Rai the former CAG has proved himself as a stooge of BJP, who was entrusted upon playing a sinister design to tarnish the image of UPA Government by his quixotic, wilful and deliberate observations in the CAG paras.

[29] Then Congress's Chief Minister Ashok Gehlot accused, "Vinod Rai's false claims on 2G spectrum, Coal scam led to UPA's defeat".