Here is the full list of all 41 WRC 6 achievements worth 1,000 gamerscore. It takes around 100-120 hours to unlock all of the achievements on Xbox One.
Reached the podium in the Rally Guanajuato México in Career mode
Completely totalled a car
Has completed a WRC 2 season and moved up to WRC
Finished a Stage without taking any damage in any mode
Reached the podium in the Vodafone Rally de Portugal in Career mode
Reached the podium in the YPF Rally Argentina in Career mode
Reached the podium in the Rally Sweden in Career mode
Has completed a Junior WRC season and moved up to WRC 2
Reached the podium in the Kennards Hire Rally Australia in Career mode
Reached the podium in the Tour de Corse - Rallye de France in Career mode
Drove into a lake
Won a Stage using only the cockpit view in solo mode
Reached the podium in the Neste Rally Finland in Career mode
Won your first Stage in online multiplayer mode
Rolled a car
Watched the full credits
Won your first Stage in solo mode
Has started a new career
Completed your first Stage in online multiplayer mode
Completed your first Stage in solo mode
Complete all Stages (excluding SSS) in solo mode
Complete all SSS in solo mode
Win all Stages (excluding SSS) in solo mode
Win all SSS in solo mode
Win your first SSS in online multiplayer mode
Drive more than 1,000Km on gravel in solo mode
Drive more than 500Km on tarmac in solo mode
Drive more than 500Km on snow in solo mode
Drive more than 5,000Km on any surface in solo mode
Complete a WRC season and become champion
Complete a Stage in each country in solo mode
Reach the podium in the Rallye Monte Carlo in Career mode
Reach the podium in the Rally Italia Sardegna in Career mode
Reach the podium in the 73rd PZM Rally Poland in Career mode
Reach the podium in the ADAC Rallye Deutschland in Career mode
Reach the podium in the Rally China - Beijing in Career mode
Reach the podium in the RallyRACC Catalunya - Rally de España in Career mode
Reach the podium in the Dayinsure Wales Rally GB in Career mode
Achieve a score of at least 90 on the driving test
Spend exactly 45 minutes conducting repairs in one session
Complete all accomplishments