He has been Commissioner of Income Tax (Appeals) International Taxation, Delhi. He was also the Director of Investigation, Mumbai and Director General Investigation, Gujarat.[6][7][8]
On 15 February 2019, he was appointed as the Election Commissioner of India and took office as the Chief Election Commissioner of India on 13 April 2021.[9]
He has been involved in 16 elections including five as chief election commissioner. He retired on 14 May 2022, Rajiv Kumar succeeded him. In, February 2024 he was appointed as a non-judicial member of Lokpal where he served till 14 May 2027.[10]