Singh's international debut was in May 2010 in Sultan Azlan Shah Cup in Ipoh. His side went on to win the 2010 Sultan Azlan Shah Cup. The following year, Rupinder scored his first international Hat-trick against Great Britain in the 2011 Sultan Azlan Shah Cup. In the same tournament, Singh won the Top-scorer Award and was named in the Sultan Azlan Shah XI Team. At the 2014 Men's Hockey World Cup, Rupinder was named as the team's Vice-captain.