Complex sentence: Nearly 6000 troops amongst the surviving units of the INA remained in Rangoon under A. D. Loganathan, surrendered as Rangoon fell, and helped keep order until the Allied forces entered the city.
Split into simpler sentences: Nearly 6000 troops amongst the surviving units of the INA remained in Rangoon under A. D. Loganathan. They surrendered as Rangoon fell and helped keep order until the Allied forces entered the city.