The new penal code law, passed last year, has been made effective throughout the country since Nov. 12.
Cambodia goes to the polls every five years, first in national elections and then in parliamentary elections.
The law will require NGOs to provide financial reports and action plans to the government.
The health service provided by more than 50 doctors will include dental care and out-patient treatment.
Thai parliament has not ruled on the meeting in part due to extreme political instability in Thailand.
Surin was once part of a wider Khmer empire that encompassed parts of modern-day Thailand and Vietnam.
The Khmer Rouge tribunal sentenced Duch to a commuted 19 years in prison, earlier this year.
More than 8,000 victims have filed with the unit and are awaiting the trial of four jailed senior Khmer Rouge leaders.
Cambodia is preparing for local commune elections in 2012 and national parliamentary elections in 2013.