On 21 April 1935 Geeverghese Mar Koorilose -V died of a heart attack. Then Titus-II Mar Thoma, Metropolitan of the sister church, arrived at Thozhiyur and held consultations with the representatives of the parishes at the Cathedral. It was a Sunday. There were two candidates, Father K.M.Kuriakose aged 52 and Father C.J.Verghese aged 28.

The Metropolitan began the meeting with prayer and spoke of the healthy co-operation between the Mar Thoma Syrian Church and the Malabar Independent Syrian Church and their mutual participation in consecrating bishops. Then he asked the members to mention their nominee. There was a pause for a few minutes. The silence was broken by Sri C. P. Chum¬mar, a leading member of the Chalisserri Parish. He, with all due respect, said they would be glad to accept whomsoever their distinguished guest nominated. The others agreed unanimously. The Metropolitan, with tears in his eyes, declared that Fr. K.M.Kuriakose, senior of the two, was to be elected and consecrated. He added that Fr. C.J.Verghese could succeed the selected nominee. Accordingly, Fr. C. J.Verghese eventually succeeded Kuriakose Mar Koorilose in 1948. The congregation gladly accepted the advice of the Mar Thoma Metropolitan. No episcopal election has been conducted in such a peaceful atmosphere since 1935.
Father K.M.Kuriakose was consecrated under the title of Mar Koorilose -VI by Titus-II Mar Thoma in association with Abraham Mar Thoma, his suffragan, on 23 January 1936. He was the head of the church till 1947. Kuriakose Mar Koorilose participated in the consecration ceremony of Juhanon Mar Timothios Episcopa and Mathews Mar Athanasios Episcopa of the sister (i.e. Mar Thoma) church in 1937. During his episcopal ministry a chapel was built at Akathiyur, three miles north of Kunnamkulam, and the St. Thomas church at Kunnam¬kulam was modified and reconstructed in 1940. The income of the church increased and some of the mortgaged properties were recovered. Unfortunately he could not lead the church on the path of peace and prosperity. Gradually his eyesight failed and for the last two years he was completely confined to bed. On 15 October 1947 he passed away.