Bok discard lured to Scotland
Gray joins the Scotland set-up following a three-season spell as South Africa's specialist breakdown coach during Heyneke Meyer's tenure, which culminated in their bronze medal finish at 2015 World Cup.
Gray's contract with the South African Rugby Union was not renewed after Meyer's resignation late last year.
Gray also assisted the Springbok Sevens side.
The move signals a return for the former Scotland age-grade internationalist from Galashiels, a Scottish Rugby employee from 1994 and 2006, when he worked as a Development Manager, Academy Manager and coach to various Scotland age-grade sides.
The award-winning inventor of the 'Collision King' technical training range said: "It's a great honour to coach any country but to be offered the opportunity to coach your own is something special indeed.
"The defensive breakdown is an area highlighted by the coaches as an area for improvement, for which I've been given a very specific brief to work alongside defence coach Matt Taylor for the seven-week period of the Six Nations.
"It's a great honour and I'm looking forward to joining up with the squad in camp in St Andrews."
Cotter said: "On behalf of the national team I'd like to welcome Richie [Gray] to our coaching set-up for the 2016 Six Nations.
"We're looking forward to adding his experience and passion to the group."
