Manik's diplomatic career began in 1997 at the North American section within the directorate of international trade relations. From 1999 to 2002, he was assigned at the embassy in Wellington with the rank of third secretary, followed by a post at the embassy in Suva with the rank of second secretary from 2002 to 2004. In 2004, he served as the chief of the legislation subsection at the secretariat of the directorate general of multilateral cooperation. Subsequently, from 2004 to 2006, he was the chief of UN operational activities subsection in the directorate of development, economic and environmental affairs.[1]
In 2007, Okto was posted as the chief of consular affairs at the consulate general[2] in San Francisco with the rank of first secretary, serving until 2011. He returned to the foreign ministry to serve as the deputy director (chief of subdirectorate) for taxation and infrastructure facilities with the directorate of diplomatic facilities from 2011 to 2013, before being assigned to the protocol and consular section of the embassy in Washington D.C. with the rank of minister counsellor from 2013 to 2017. He then held the position of deputy director (chief of subdirectorate) for personnel and general affairs from 2017 to 2018 at the secretariat of the directorate general of law and international treaties.[1]
On 4 April 2018, Okto became the chief of the legal and administration for the ministry and representatives in the foreign ministry.[3] In February 2021, Okto was nominated as ambassador of Indonesia to Timor-Leste.[4] After passing the House of Representatives assessment in July,[5] he was installed on 25 October 2021.[6] He presented his credentials to President of Timor-Leste Francisco Guterres on 13 December 2021.[7] During his tenure, he was involved in the Indonesia-Timor Leste business forum in 2022.[8] He also facilitated visits to Indonesia by Timor-Leste president José Ramos-Horta in 2022, which was followed by the signing of a memorandum of understanding,[9] and Prime Minister Xanana Gusmao in 2024.[10] On 31 February 2023, Okto announced Indonesia's visa-free policy for citizens of Timor-Leste entering via land borders, which was enacted since the 13th of that month as part of efforts to strengthen bilateral relations between the two countries.[11]
Okto was nominated for ambassador to Papua New Guinea and Solomon Islands by President Prabowo Subianto in July 2025.[12] His nomination was approved by the House of Representatives in a session on 8 July 2025.[13] Shortly afterwards, Okto announced his departure from Timor-Leste in late August.[14] He was sworn in as ambassador to Papua New Guinea and Solomon Islands on 19 December 2025.[15]
