The April 1960 Government Gazette declared that Regiment Oos-Rand was activated on 1 January 1960 as a Citizen Force Unit.

d. Regiment Andries Pretorius, a Motorised Infantry Battalion, at Germiston e. Witwatersrand Rifles, a Motorised Infantry Battalion, whose members were indeed allotted from the East Rand area, was headquartered in Johannesburg, and who, for the aforesaid reason, was perhaps less well known to the East Rand.

In 1990 the regiment was converted to a mechanised infantry battalion and participated in excersize "sweepslag" at the Army Battle School located at the Lohatla.

It is located in the Northern Cape province of South Africa and is home to the SA Army Combat Training Centre By 1995, the unit strength declined much due to the elimination of conscript national service.

[3][4] In August 2019, 52 Reserve Force units had their names changed to reflect the diverse military history of South Africa.

[6] The regiment's new title is in honor of Oliver Tambo, who for many years served as the President of the African National Congress and was co-founder of uMkhonto we Sizwe.

Regiment East Rand specialised in 81 mm Mortar platoons, Medics, Signals and Drivers 11 Field Postal Unit