In Indonesia's historical records Ben Mang Reng Say along with Frans Seda plays an important role in the Rome meeting[1] under Foreign Minister Adam Malik and General Murtopo in order to discuss East Timor's peaceful integration into the unitary state of Indonesia territory.

Apparently this line of work was not for him, so he resign from his position as a police and continued his studies in Meer Uitgebreid Lager Onderwijs /MULO in Makasar (1949–1951).

On 31 December 1964, Say was appointed as a member of The People's Representative Council of Mutual Assistance (Indonesian: Dewan Perwakilan Rakyat Gotong Royong, DPR-GR).

[3] For a year (1975–1976) Say was appointed as The Ambassador of Indonesia for the government of the Republic of Portugal, at that time he was sent to Rome to discuss the steps for East Timor integration to Indonesian territory, but the meeting that supposed to run peacefully ended with bloodshed, Six months he work, and managed to make a "courageous" report to the United Nations.

he admitted that about 200 people killed by army bullets during demonstrations demanding the independence of East Timor.