An ex-serviceman allegedly committed suicide over the issue of One Rank One Pension scheme (OROP) here, police said today.. The 70-year-old ex-serviceman Ram Kishan Grewal committed suicide by consuming poison at a park in New Delhi area yesterday evening.. Police said he along with some other ex-servicemen was in the process of submitting a memorandum to the Defence Ministry over the issue of OROP.. According to his friends, Grewal had been upset over the issue for sometime.. Ex-servicemen have been protesting over the OROP scheme introduced by the government.