Nellikunnel went to St. Mary’s High School, Mariapuram before in 1988 when he began his priestly formation at the Minor Seminary of the Eparchy of Kothamangalam.
He attended the St. Thomas Apostolic Seminary, Vadavathoor for the philosophical and theological studies.
He served in various assistant pastor roles in the Eparchy before going back for studies at the Pontifical Gregorian University in Rome for a Licentiate in Philosophy and a Doctorate in Philosophy from the Pontifical University of Saint Thomas Aquinas.
He then came back to India for Pastoral duties until in 2010 when he was appointed the Eparchial Chancellor and Secretary to the Bishop by Mathew Anikuzhikattil.
[1] In 2018, he was appointed to succeed Mathew Anikuzhikattil as the Eparch of the Syro-Malabar Catholic Eparchy of Idukki.